Air conditioner for railway vehicles

ABSTRACT

An air conditioner for railway vehicles controlled in accordance with the air temperature in the car and data on at least one selected from the group consisting of underfoot temperature, radiant heat, air flow, humidity, outside air temperature, number of passengers and door opening operation. In this way, environment conditions which momentarily change are detected so as to prevent excessive cooling or heating in the car.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to the control of an air conditioner forrailway vehicles for maintaining an optimum temperature within thevehicles.

2. Description of the Related Art

Examples of air-cooling railway vehicles using conventional airconditioners will be explained with reference to FIG. 64 schematicallyshowing a train car, the circuit diagrams in FIGS. 65 and 67, theflowcharts of the controlling operation in FIGS. 66 and 68, and FIGS. 69to 71 schematically showing the concepts of the controlling operation.

FIG. 64 is a schematic view of the structure of a train car equippedwith a conventional air conditioner and the flow of data therewithin.This is similar to the structure of a train car equipped with an airconditioner and the flow of data therewithin described in JapaneseUtility Model Laid-Open No. Hei 2-41037. In FIG. 64, the referencenumeral 1 denotes a train car, 2 an air conditioner mounted on the upperpart of the train car 1, 3 a heating/cooling power controller forcontrolling the heating/cooling power by varying the power of acompressor provided in the air conditioner 2, 4 an air conditionercontrol unit having a means for determining the heating/cooling power, 5a control switch portion by which a train operator selects the heatingor cooling operation, ON or OFF and sets the target temperature in thecar, 6 a temperature detector which is composed of a thermistor or thelike so as to detect the temperature of the air returned from the car, 7a heated/cooled air supply opening and 8 a suction opening for suckingthe air from the car.

FIG. 65 is a circuit diagram of the air conditioner 4. The airconditioner 4 is composed of an input circuit 41, a CPU 42, a memory 43and an output circuit 44. An output from the control switch portion 5 inthe train operator's compartment and an output from the temperaturedetector 6 are input to the input circuit 41. The heating/cooling powercontroller 3 controls the power of the compressor in accordance with theoutput of the output circuit 44. The CPU 42 calculates the optimumheating/cooling power, and the result of the calculation is supplied tothe output circuit 44.

The operation of the air conditioner 4 will now be explained withreference to FIG. 66. A conventional air cooling device of this typecontrols the air temperature so as to be the target temperature or inthe vicinity thereof while calculating the optimum cooling power fromthe difference between the temperature of the air to be controlled andthe target temperature. This control method is generally calledproportional control.

The proportional control method will be explained in the following withreference to the flowchart in FIG. 66. At step F1, the air conditioner 4of the train is first turned ON by a train operator, and the targettemperature T0 is set at step F2. At step F3, a preset time formeasuring the temperature is allowed to pass, and the air temperature Tnin the car is detected at step F4. The temperature difference dT betweenthe target temperature T0 and the air temperature Ta in the car isobtained at step F5. At step F6, the optimum cooling power is newlycalculated from the temperature difference dT, in accordance with thecooling power chart shown in FIG. 69. When the optimum cooling power isobtained in this way, the cooling power for the current coolingoperation is changed at step F7, and the cooling operation is continuedat the newly changed cooling power at step F8.

In such proportional control, however, since the cooling operation isconducted at the cooling power determined by the temperature differencebetween the temperature of the air to be controlled and the targettemperature, it is difficult to reach the target temperature dependingupon the condition of the load, as shown in FIG. 70 which shows theconcept of the controlling operation. For example, even if the coolingpower is reduced, the air temperature in the car is sometimes lowered toa temperature lower than the target temperature after the time t1.

To solve this problem, PID control is disclosed in Japanese UtilityModel Laid-Open No. Hei 2-41037. In PID control, not only is thetemperature difference between the temperature of the air to becontrolled and the target temperature detected, but also the precedenttemperature difference is stored, and the optimum cooling power iscalculated from the detected temperature difference and the precedenttemperature difference. Therefore, the air temperature in the car doesnot remain at a different temperature from the target temperature for along time but is easily controlled to be the target temperature.However, the air temperature in the car is susceptible to a change inthe load such as the outside air temperature and the number ofpassengers, and it is difficult to follow the change in the load whichoccurs in a short time such as the increase in the amount of ventilatingair due to the opening and closing of the doors and the passengersgetting on and off. In addition, PID control is disadvantageous in thatthe calculation is complicated and in that a large memory capacity isrequired.

In the control method shown by the circuit diagram in FIG. 67 and theflowchart shown in FIG. 68, a fuzzy theory is applied to the control ofthe air conditioner so as to enable simple control and the attainment ofthe target temperature. The electric circuit shown in FIG. 67 has aregion 431 of the memory 43 for storing a previously measuredtemperature difference dT.

This control method will be explained with reference to the flowchart inFIG. 68. The air conditioner of the train is first turned on by a trainoperator or the like at step F11, and the target temperature is set atstep F12. At step F13, a preset time for measuring the temperature isallowed to pass, and the air temperature in the car is detected at stepF14. The temperature difference dT between the target temperature andthe air temperature in the car is obtained at step F15. At step F16,judgement is made as to whether or not the current measurement is afirst measurement. If this is a first measurement, this temperaturedifference is stored in the memory 43 as a precedent temperaturedifference dTs. On the other hand, if this is a second or latermeasurement, the variance St of temperature difference with time, whichis the difference between the precedent temperature difference dTs andthe current temperature difference dT, is obtained at step F17. It ispossible to determine whether the temperature in the car is stable orhas changed in a short time from the variance of temperature differencewith time. At step F18, the optimum cooling power is calculated byapplying the fuzzy theory. FIG. 71 shows the image of the fuzzy rule. Asshown in FIG. 71, the optimum cooling power for making the temperaturein the car equal to the target temperature is inferred from thetemperature difference dT between the air temperature in the car and thetarget temperature, and the variance St of temperature difference withtime. For example, if the temperature in the car is lower than both thetarget temperature and the previously measured temperature, it is judgedthat the air-cooling is excessive, and the cooling power is reduced. Onthe other hand, if the temperature in the car is higher than both thetarget temperature and the previously measured temperature, it is judgedthat the air-cooling is insufficient, and the cooling power isincreased. If there is no temperature difference between the airtemperature in the car and the target temperature and there is nodifference in the current temperature change and the precedenttemperature change, it is judged that the air temperature in the car isbeing maintained in a good state and the cooling power is maintained asit is. When a correction value for the cooling power is obtained in thisway, the cooling power for the current cooling operation is corrected bythe correction value at step F18, and the cooling operation is continuedat the newly changed cooling power at step F20. The temperaturedifference dT between the target temperature and the air temperature inthe car is stored in the memory 43 as a precedent temperature differencedTs, and there is then a pause until the next temperature detectiontakes place.

Since the cooling operation is conducted while determining thecorrection value in accordance with the temperature in the car and thetemperature change in this way, the temperature in the car is nevermaintained at a different temperature from the target temperature forvery long and it is possible to follow well the change in the load. Inaddition, since the amount of data stored in the memory 43 need only bea precedent temperature difference, it is possible to control thecooling power relatively simply.

As explained in the related art, in a conventional air conditioner, theheating/cooling operation is conducted while changing theheating/cooling power to the optimum value using the correction valueinferred from the temperature difference between the temperature in thecar and the target temperature and the variance of temperaturedifference with time in accordance with the fuzzy rule so that thetemperature in the car is constantly comfortable for the passengers. Oneof the important factors to be taken into consideration in determiningthe heating/cooling power is the load of the heating/cooling system. Theload of the heating/cooling system thermally influences the space beingheated or cooled. It is, for example, the outside air temperature whichinfluences the air temperature in the car due to ventilation or by heattransferred from the wall, and passengers who evolve heat in the car. Inthe case of railway vehicles which run a long distance, the outside airtemperature changes momentarily. In the case of subways, the platformsof some stations are air-conditioned, and the outside air temperature isdifferent when traveling through tunnels than while stopping atstations. Since the railway vehicles have a number of large windows, theinfluence of solar radiation through the windows is large in allvehicles except subway trains, and its influence changes greatlyaccording to the direction of travel and when vehicles run throughtunnels. In addition, a great many passengers get off and on every timea train reaches a station, and sometimes, a car is heavily crowded in acertain section while there are few passengers in other next sections.

Since the heat evolved by the passengers greatly influences theheating/cooling operation, if the number of passengers is rapidlyreduced, the temperature in the car is lowered, while if the number ofpassengers is rapidly increased, the temperature in the car is raised,Simultaneously with passengers getting off and on, a large amount of airventilates, and the air temperature in the car changes due to theinfluence of the outside air temperature. It can be said that a typicalcharacteristic of the air-conditioning in railway vehicles is that theload constantly changes in this way. When the load is large, even if thetemperature change and the difference between the temperature differenceand the precedent temperature difference are the same as in the case ofa small load, it cannot be said that the temperature in the car will bechanged in the same way by the same correction value for the coolingpower. The outside air temperature will be cited as an example of theload of the cooling system. When the outside temperature is high, sincea large amount of heat transfers to the inside of the car through thewall and hot air enters the inside of the car due to drafts or byventilation, the temperature in the car is difficult to lower byincreasing the cooling power in the same way as in the case of a loweroutside air temperature and, if the cooling power is reduced, thetemperature in the car rises in a short time. On the other hand, if theoutside air temperature is low, even with a little increase in thecooling power, the temperature in the car is easily lowered and, even ifthe cooling power is reduced, the temperature in the car is not raisedso much. The same may be said of the amount of radiant heat by solarradiation or the like and the number of passengers. In this way, thestate of the ambient load exerts great influence on the operation of theair conditioner. In such cases, it is impossible to calculate thecorrection value with due consideration of the load by a conventionalcalculation method. As a result, it is impossible to follow the changein the load and the temperature in the car disadvantageously becomes toolow or too high.

In the above-described control methods, control is carried out on theassumption that the temperature in the car is kept constant. The humanthermesthesia, however, is not determined merely by the air temperaturebut it is determined by the amount of heat produced within the humanbody and the amount of heat dissipated to the outside of the human body.If the amount of dissipated heat is large, a human being feels cold,while if it is small, he feels hot. The amount of dissipated heat isdetermined by temperature, radiation, air flow, humidity, etc. Forexample, if the outside air temperature is high, the amount of heatdissipated to the outside of the human body is reduced, and the humanbeing feels hot, while if the outside air temperature is low, the amountof heat dissipated to the outside of the human body is increased, andthe human being feels cold. As to radiation, if there is warm heatradiation, the amount of heat dissipated to the outside of the humanbody is reduced, while if there is cold heat radiation, the amount ofheat dissipated to the outside of the human body is increased. As to airflow, if a large amount of wind blows against the human body, the heaton the surface of the human body is lost and the amount of heatdissipated to the outside of the human body is increased, while if theamount of wind is small, the amount of dissipated heat is reduced. Indissipating heat, a human being dissipates water out of the human body.If the balance between the amount of heat produced in the human body andthe amount of dissipated heat is lost, the human being perspires inorder to dissipate more heat. When the perspiration is evaporated, theheat on the surface of the human body is lost, thereby increasing theamount of dissipated heat and controlling the body temperature. However,if the ambient humidity is high, perspiration is unlikely to evaporate,and the amount of heat dissipated from the human body is reduced, sothat the human being feels hot. In this way, temperature, radiation, airflow, humidity, etc. play an important role in the human thermesthesia.In heating or cooling a certain space, the temperature differencebetween the upper portion and the lower portion must be particularlytake into consideration. The human thermesthesia is said to bedetermined by the temperature at his feet. Even if the temperature atthe upper half of the body is high, if the temperature at his feet islow, the human being feels cold. On the other hand, even if thetemperature at the upper half of the body is comparatively low, if thetemperature at his feet is high, the human being feels warm. In heatingor cooling a car, since the doors are opened when the train reaches astation and a large amount of ventilating air flows, the temperature inthe car is unlikely to become stable. When a great number of passengersare in the car as in a commuter train, the air is unlikely to flowvertically in the car. For these reasons, a temperature difference isapt to arise between the upper portion and the lower portion. It istherefore important to heat or cool the car in due consideration of thetemperature difference between the upper portion and the lower portionof the car.

In conventional control methods, however, the heating/cooling operationis carried out so that the temperature in the car is kept constant, sothat the human thermesthesia changes with a change in the radiation, airflow or the temperature change between the upper portion and the lowerportion of the car. The passengers therefore feel unfavorably hot orcold in spite of the target temperature.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to solve theabove-described problems in the related art and to provide an airconditioner for railway vehicles which is capable of controlling thetemperature in the car in accordance with information on the outside airtemperature, the number of passengers, opening or closing of the doors,radiation, air flow, humidity and temperature difference between theupper portion and the lower portion of the car so as to constantlyprovide a comfortable environment for the passengers and prevent anexcessive heating/cooling operation so as to reduce the energyconsumption.

To achieve this end, in a first aspect of the present invention, thereis provided an air conditioner for railway vehicles comprising:

(a) a warm/cool air current generator for generating a warm air currentin the heating operation and a cool air current in the coolingoperation;

(b) a car temperature detector provided in the vicinity of the ceilingof the car so as to detect the air temperature in the car;

(c) an underfoot temperature detector provided in the vicinity of thefloor of the car so as to detect the air temperature in the vicinity ofthe passengers' feet;

(d) a target temperature correcting means for inferring thethermesthesia of the passengers on the basis of the output of the cartemperature detector and the output of the underfoot temperaturedetector and correcting the target temperature in accordance with theresult of the inference;

(e) an optimum heating/cooling power calculator for calculating theoptimum heating/cooling power on the basis of the temperature differencebetween the corrected target temperature and the air temperature in thecar; and

(f) a heating/cooling power controller for controlling the warm/cool aircurrent generator in accordance with the output of the optimumheating/cooling power calculator;

wherein the target temperature correcting means infers the thermesthesiaof the passengers such as "hot" and "cold" on the basis of thetemperature difference between the upper portion and the lower portionof the car obtained from the output of the car temperature detector andthe output of the underfoot temperature detector, and corrects thetarget temperature in accordance with the result of the level ofthermesthesia so that the target temperature is lowered when the resultof the inference is "the passengers feel hot" while the targettemperature is raised when the result of the inference is "thepassengers feel cold".

In a second aspect of the present invention, there is provided an airconditioner for railway vehicles comprising: the above-describedelements (a) to (f); and

a radiant heat quantity detector provided at an appropriate location inthe car so as to detect the quantity of radiant heat;

wherein the target temperature correcting means infers the thermesthesiaof the passengers such as "hot" and "cold" from the temperaturedifference between the upper portion and the lower portion of the carobtained from the output of the car temperature detector and the outputof the underfoot temperature detector and on the basis of the output ofthe radiant heat quantity detector, and corrects the target temperaturein accordance with the result of the level of the thermesthesia so thatthe target temperature is lowered when the result of the inference is"the passengers feel hot" while the target temperature is raised whenthe result of the inference is "the passengers feel cold".

In a third aspect of the present invention, there is provided an airconditioner for railway vehicles comprising: the above-describedelements (a) to (f); and

an anemometer provided at an appropriate location in the car so as todetect the velocity of the air current in the car;

wherein the target temperature correcting means infers the thermesthesiaof the passengers such as "hot" and "cold" from the temperaturedifference between the upper portion and the lower portion of the carobtained from the output of the car temperature detector and the outputof the underfoot temperature detector and on the basis of the output ofthe anemometer, and corrects the target temperature in accordance withthe result of the level of the thermesthesia so that the targettemperature is lowered when the result of the inference is "thepassengers feel hot" while the target temperature is raised when theresult of the inference is "the passengers feel cold".

In a fourth aspect of the present invention, there is provided an airconditioner for railway vehicles comprising: the above-describedelements (a) to (f);

a radiant heat quantity detector provided at an appropriate location inthe car so as to detect the quantity of radiant heat; and

a hygrometer provided at an appropriate location in the car so as todetect the reltaive humidity in the car;

wherein the target temperature correcting means infers the thermesthesiaof the passengers such as "hot" and "cold" from the temperaturedifference between the upper portion and the lower portion of the carobtained from the output of the car temperature detector and the outputof the underfoot temperature detector and on the basis of the output ofthe radiant heat quantity detector, and corrects the target temperaturein accordance with the result of the level of the thermesthesia so thatthe target temperature is lowered then the result of the inference is"the passengers feel hot" while the target temperature is raised whenthe result of the inference is "the passengers feel cold", and furthercorrects the target temperature in accordance with the output of thehygrometer so that the target temperature is lowered when the humidityis high while the target temperature is raised when the humidity is low.

In a fifth aspect of the present invention, there is provided an airconditioner for railway vehicles comprising: the above-describedelements (a) to (f);

an anemometer provided at an appropriate location in the car so as todetect the velocity of the air current in the car; and

a hygrometer provided at an appropriate location in the car so as todetect the reltaive humidity in the car;

wherein the target temperature correcting means infers the thermesthesiaof the passengers such as "hot" and "cold" from the temperaturedifference between the upper portion and the lower portion of the carobtained from the output of the car temperature detector and the outputof the underfoot temperature detector and on the basis of the output ofthe anemometer, and corrects the target temperature in accordance withthe result of the level of the thermesthesia so that the targettemperature is lowered when the result of the inference is "thepassengers feel hot" while the target temperature is raised when theresult of the inference is "the passengers feel cold", and furthercorrects the target temperature in accordance with the output of thehygrometer so that the target temperature is lowered when the humidityis high while the target temperature is raised when the humidity is low.

In a sixth aspect of the present invention, there is provided an airconditioner for railway vehicles comprising:

(a) a warm/cool air current generator for generating a warm air currentin the heating operation and a cool air current in the coolingoperation;

(b) a car temperature detector provided in the vicinity of the ceilingof the car so as to detect the air temperature in the car;

(c) a heating/cooling power correction value data detector provided at apredetermined location in the car;

(d) a target temperature correcting means for inferring thethermesthesia of the passengers on the basis of the output of the cartemperature detector and the output of an underfoot temperature detectorand correcting the target temperature in accordance with the result ofthe inference;

(e) an optimum heating/cooling power calculator for calculating theoptimum heating/cooling power on the basis of the temperature differencebetween the corrected target temperature and the air temperature in thecar; and

(f) a heating/cooling power controller for controlling the warm/cool aircurrent generator in accordance with the output of the optimumheating/cooling power calculator.

In a seventh aspect of the present invention, there is provided an airconditioner for railway vehicles comprising the above-described elements(a) to (f) of the air conditioner provided in the sixth aspect of thepresent invention;

and a heating/cooling power correcting means;

wherein the heating/cooling power correction value data detector (c) isa radiant heat detector for detecting radiant heat and, on the basis ofthe output of the radiant heat detector, the heating/cooling correctingmeans corrects the output of the optimum heating/cooling powercalculator (e) in the cooling operation so that when the output of theoptimum heating/cooling power calculator (e) indicates that the coolingpower is increased, the cooling power is slightly increased to aslightly larger value than the calculated value if the quantity ofradiant heat is large, while the cooling power is increased to a smallervalue than the calculated value if the quantity of radiant heat issmall, and on the other hand, when the output of the optimumheating/cooling power calculator (e) indicates that the cooling power isreduced, the cooling power is reduced to a slightly smaller value thanthe calculated value if the quantity of radiant heat is large, while thecooling power is reduced to a slightly larger value than the calculatedvalue if the quantity of radiant heat is small, and corrects the outputof the optimum heating/cooling power calculator (e) in the heatingoperation so that when the output of the optimum heating/cooling powercalculator (e) indicates that the heating power is increased, theheating power is increased to a slightly smaller value if the quantityof radiant heat is large, while the heating power is increased to aslightly larger value than the calculated value if the radiant heat islow, and on the other hand, when the output of the optimumheating/cooling power calculator (e) indicates that the heating power isreduced, the heating power is reduced to a slightly larger value thanthe calculated value if the quantity of radiant heat is large, while theheating power is reduced to a slightly smaller value than the calculatedvalue if the quantity of radiant heat is small.

In an eighth aspect of the present invention, there is provided an airconditioner for railway vehicles comprising the above-described elements(a) to (f) of the air conditioner provided in the sixth aspect of thepresent invention,

and a heating/cooling power correcting means, wherein theheating/cooling power correction value data detector (c) is an outsideair temperature detector for detecting the temperature of the outsideair and, on the basis of the output of the outside air temperaturedetector, the heating/cooling correcting means corrects the output ofthe optimum heating/cooling power calculator (e) in the coolingoperation so that when the output of the optimum heating/cooling powercalculator (e) indicates that the cooling power is increased, thecooling power is increased to a slightly larger value than thecalculated value if the outside air temperature is high, while thecooling power is increased to a slightly smaller value if the outsideair temperature is low, and on the other hand, when the output of theoptimum heating/cooling power calculator (e) indicates that the coolingpower is reduced, the cooling power is reduced to a slightly smallervalue than the calculated value if the temperature of the outside air ishigh, while the cooling power is reduced to a slightly larger value thanthe calculated value if the temperature of the outside is low, andcorrects the output of the optimum heating/cooling power calculator (e)in the heating operation so that when the output of the optimumheating/cooling power calculator (e) indicates that the heating power isincreased, the heating power is increased to a slightly smaller valuethan the calculated value if the temperature of the outside air is high,while the heating power is increased to a slightly larger value than thecalculated value if the temperature of the outside air is low, and onthe other hand, when the output of the optimum heating/cooling powercalculator (e) indicates that the heating power is reduced, the heatingpower is reduced to a slightly larger value than the calculated value ifthe temperature of the outside air is high, while the heating power isreduced to a slightly smaller value than the calculated value if thetemperature of the outside air is low.

In a ninth aspect of the present invention, there is provided an airconditioner for railway vehicles comprising the above-described elements(a) to (f) of the air conditioner provided in the sixth aspect of thepresent invention;

and a heating/cooling power correcting means; wherein theheating/cooling power correction value data detector (c) is a passengernumber detector for detecting the number of passengers in the car and,on the basis of the output of the passenger number detector, theheating/cooling correcting means corrects the output of the optimumheating/cooling power calculator (e) in the cooling operation so thatwhen the output of the optimum heating/cooling power calculator (e)indicates that the cooling power is increased, the cooling power isincreased to a slightly larger value than the calculated value if thenumber of passengers is large, while the cooling power is increased to aslightly smaller value than the calculated value if the number ofpassengers is small, and on the other hand, when the output of theoptimum heating/cooling power calculator (e) indicates that the coolingpower is reduced, the cooling power is reduced to a slightly smallervalue than the calculated value if the number of passengers is large,while the cooling power is reduced to a slightly larger value than thecalculated value if the number of passengers is small, and corrects theoutput of the optimum heating/cooling power calculator (e) in theheating operation so that when the output of the optimum heating/coolingpower calculator (e) indicates that the heating power is increased, theheating power is increased to a slightly smaller value than thecalculated value if the number of passengers is large, while the heatingpower is increased to a slightly larger value than the calculated valueif the number of passengers is low, and on the other hand, when theoutput of the optimum heating/cooling power calculator (e) indicatesthat the heating power is reduced, the heating power is reduced to aslightly larger value than the calculated value if the number ofpassengers is large, while the heating power is reduced to a slightlysmaller value than the calculated value if the number of passengers islow.

In a tenth aspect of the present invention, there is provided an airconditioner for railway vehicles comprising the above-described elements(a) to (f) of the air conditioner provided in the sixth aspect of thepresent invention;

and a heating/cooling power correcting means; wherein theheating/cooling power correction value data detector (c) includes anoutside air temperature detector attached to the outside of the car soas to detect the temperature of the outside air and a passenger numberdetector for detecting the number of passengers in the car, and theheating/cooling correcting means infers the degree of the load of theair-conditioning system from the output of the outside air temperaturedetector and the output of the passenger number detector and correctsthe output of the optimum heating/cooling power calculator (e) so thatwhen the output of the optimum heating/cooling power calculator (e)indicates that the heating/cooling power is increased, theheating/cooling power is increased to a slightly larger value than thecalculated value if the load of the air-conditioning system is large,while the heating/cooling power is increased to a slightly smaller valuethan the calculated value if the load of the air-conditioning system issmall, and on the other hand, when the output of the optimumheating/cooling power calculator (e) indicates that the heating/coolingpower is reduced, the heating/cooling power is reduced to a slightlysmaller value than the calculated value if the load is large, while theheating/cooling power is reduced to a slightly larger value than thecalculated value if the load is small.

In an eleventh aspect of the present invention, there is provided an airconditioner for railway vehicles comprising the above-described elements(a) to (f) of the air conditioner provided in the sixth aspect of thepresent invention,

wherein the heating/cooling power correction value data detector (c) isa door opening information detector for transmitting a signal indicatingthat the doors are open to a control unit of the air conditioner througha control switch, and the optimum heating/cooling power output from theoptimum heating/cooling power calculator (e) is increased.

In a twelfth aspect of the present invention, there is provided an airconditioner for railway vehicles comprising the above-described elementsthe air conditioner provided in any of the first to fifth aspects of thepresent invention; and

a memory for storing the temperature difference between the temperatureof the air in the car and the corrected target temperature;

wherein the temperature difference between the temperature of the air inthe car and the corrected target temperature is calculated atpredetermined time intervals, the heating/cooling power is calculatedfrom the temperature difference between the calculated temperaturedifference and the precedent temperature difference stored in thememory, and the precedent temperature difference stored in the memory isreplaced by the newly calculated temperature difference.

In a thirtieth aspect of the present invention, there is provided an airconditioner for railway vehicles comprising the above-described elementsthe air conditioner provided in any of the sixth to eleventh aspects ofthe present invention; and

a memory for storing the temperature difference between the airtemperature in the car and the corrected target temperature;

wherein the temperature difference between the air temperature in thecar and the corrected target temperature is calculated at predeterminedtime intervals, the heating/cooling power is calculated from thetemperature difference between the calculated temperature difference andthe precedent temperature difference stored in the memory, and theprecedent temperature difference stored in the memory is replaced by thenewly calculated temperature difference.

The above and other objects, features and advantages of the presentinvention will become clear from the following description of thepreferred embodiments thereof, taken in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 schematically shows an embodiment of an air conditioner forrailway vehicles according to the present invention;

FIG. 2 is a block diagram of an example of control unit of an airconditioner for railway vehicles according to the present invention;

FIG. 3 is a flowchart of an example of the controlling operation of anair conditioner for railway vehicles according to the present invention;

FIG. 4 schematically shows another embodiment of an air conditioner forrailway vehicles according to the present invention;

FIG. 5 is a block diagram of another example of control unit of an airconditioner for railway vehicles according to the present invention;

FIG. 6 is a flowchart of another example of the controlling operation ofan air conditioner for railway vehicles according to the presentinvention;

FIG. 7 shows the concept of an example of fuzzy rule for inferringthermesthesia;

FIG. 8 shows the concept of an example of the correction value for thetarget temperature determined by thermesthesia;

FIG. 9 schematically shows still another embodiment of an airconditioner for railway vehicles according to the present invention;

FIG. 10 is a block diagram of still another example of control unit ofan air conditioner for railway vehicles according to the presentinvention;

FIG. 11 is a flowchart of still another example of the controllingoperation of an air conditioner for railway vehicles according to thepresent invention;

FIG. 12 shows the concept of another example of fuzzy rule for inferringthermesthesia;

FIG. 13 shows the concept of another example of the range of correctionvalue for the target temperature determined by thermesthesia;

FIG. 14 schematically shows a further embodiment of an air conditionerfor railway vehicles according to the present invention;

FIG. 15 is a block diagram of a further example of control unit of anair conditioner for railway vehicles according to the present invention;

FIG. 16 is a flowchart of a further example of the controlling operationof an air conditioner for railway vehicles according to the presentinvention;

FIG. 17 shows the concept of an example of the range of correction valuefor the target temperature determined by a relative humidity;

FIG. 18 schematically shows a still further embodiment of an airconditioner for railway vehicles according to the present invention;

FIG. 19 is a block diagram of a still further example of control unit ofan air conditioner for railway vehicles according to the presentinvention;

FIG. 20 is a flowchart of a still further example of the controllingoperation of an air conditioner for railway vehicles according to thepresent invention;

FIG. 21 schematically shows a still further embodiment of an airconditioner for railway vehicles according to the present invention;

FIG. 22 is a block diagram of a still further example of control unit ofan air conditioner for railway vehicles according to the presentinvention;

FIG. 23 schematically shows a still further embodiment of an airconditioner for railway vehicles according to the present invention;

FIG. 24 is a block diagram of a still further example of control unit ofan air conditioner for railway vehicles according to the presentinvention;

FIG. 25 is a flowchart of a still further example of the controllingoperation of an air conditioner for railway vehicles according to thepresent invention;

FIG. 26 schematically shows a still further embodiment of an airconditioner for railway vehicles according to the present invention;

FIG. 27 is a block diagram of a still further example of control unit ofan air conditioner for railway vehicles according to the presentinvention;

FIG. 28 is a flowchart of a still further example of the controllingoperation of an air conditioner for railway vehicles according to thepresent invention;

FIG. 29 schematically shows a still further embodiment of an airconditioner for railway vehicles according to the present invention;

FIG. 30 is a block diagram of a still further example of control unit ofan air conditioner for railway vehicles according to the presentinvention;

FIG. 31 is a flowchart of a still further example of the controllingoperation of an air conditioner for railway vehicles according to thepresent invention; FIG. 24 is a block diagram of a still further exampleof control unit of an air conditioner for railway vehicles according tothe present invention;

FIG. 32 schematically shows a still further embodiment of an airconditioner for railway vehicles according to the present invention;

FIG. 33 is a block diagram of a still further example of control unit ofan air conditioner for railway vehicles according to the presentinvention;

FIG. 34 is a flowchart of a still further example of the controllingoperation of an air conditioner for railway vehicles according to thepresent invention;

FIG. 35 schematically shows a still further embodiment of an airconditioner for railway vehicles according to the present invention;

FIG. 36 is a block diagram of a still further example of control unit ofan air conditioner for railway vehicles according to the presentinvention;

FIG. 37 is a flowchart of a still further example of the controllingoperation of an air conditioner for railway vehicles according to thepresent invention;

FIG. 38 shows the concept of a door coefficient;

FIG. 39 shows the concept of the controlling operation of the embodimentshown in FIG. 35;

FIG. 40 is a flowchart of a still further example of the controllingoperation of an air conditioner for railway vehicles according to thepresent invention;

FIG. 41 is a block diagram of a still further example of control unit ofan air conditioner for railway vehicles according to the presentinvention;

FIG. 42 is a flowchart of a still further example of the controllingoperation of an air conditioner for railway vehicles according to thepresent invention;

FIG. 43 is a block diagram of a still further example of control unit ofan air conditioner for railway vehicles according to the presentinvention;

FIG. 44 is a flowchart of a still further example of the controllingoperation of an air conditioner for railway vehicles according to thepresent invention;

FIG. 45 is a block diagram of a still further example of control unit ofan air conditioner for railway vehicles according to the presentinvention;

FIG. 46 is a flowchart of a still further example of the controllingoperation of an air conditioner for railway vehicles according to thepresent invention;

FIG. 47 is a block diagram of a still further example of control unit ofan air conditioner for railway vehicles according to the presentinvention;

FIG. 48 is a flowchart of a still further example of the controllingoperation of an air conditioner for railway vehicles according to thepresent invention;

FIG. 49 is a block diagram of a still further example of control unit ofan air conditioner for railway vehicles according to the presentinvention;

FIG. 50 is a block diagram of a still further example of control unit ofan air conditioner for railway vehicles according to the presentinvention;

FIG. 51 is a flowchart of a still further example of the controllingoperation of an air conditioner for railway vehicles according to thepresent invention;

FIG. 52 is a block diagram of a still further example of control unit ofan air conditioner for railway vehicles according to the presentinvention;

FIG. 53 is a flowchart of a still further example of the controllingoperation of an air conditioner for railway vehicles according to thepresent invention;

FIGS. 54(A) to 54(C) show the concept of the controlling operation of aconventional air conditioner carried out when a load changes;

FIGS. 55(A) to 55(C) show the concept of the controlling operation of anair conditioner according to the present invention carried out when theload in FIGS. 54(A) to 54(C) changes;

FIG. 56 is a block diagram of a still further example of control unit ofan air conditioner for railway vehicles according to the presentinvention;

FIG. 57 is a flowchart of a still further example of the controllingoperation of an air conditioner for railway vehicles according to thepresent invention;

FIG. 58 is a block diagram of a still further example of control unit ofan air conditioner for railway vehicles according to the presentinvention;

FIG. 59 is a flowchart of a still further example of the controllingoperation of an air conditioner for railway vehicles according to thepresent invention;

FIG. 60 is a block diagram of a still further example of control unit ofan air conditioner for railway vehicles according to the presentinvention;

FIG. 61 is a flowchart of a still further example of the controllingoperation of an air conditioner for railway vehicles according to thepresent invention;

FIGS. 62(A) to 62(C) show the concept of the controlling operation of anair conditioner according to the present invention carried out when aload changes;

FIGS. 63(A) to 63(C) show the concept of the controlling operation of aconventional air conditioner carried out when the load in FIGS. 62(A) to62(C) changes;

FIG. 64 schematically shows an example of a conventional air conditionerfor railway vehicles;

FIG. 65 is a block diagram of an example of control unit of aconventional air conditioner for railway vehicles;

FIG. 66 is a flowchart of an example of the controlling operation of aconventional air conditioner for railway vehicles;

FIG. 67 is a block diagram of another example of control unit of aconventional air conditioner for railway vehicles;

FIG. 68 is a flowchart of another example of the controlling operationof a conventional air conditioner for railway vehicles;

FIG. 69 shows the concept of a conventional controlling method;

FIGS. 70(A) and 70 (B) show the concept of a conventional controllingoperation;

FIG. 71 shows the concept of a fuzzy rule for obtaining the correctionvalue of the heating/cooling power in another conventional airconditioner for railway vehicles; and

FIGS. 72A, 72B show the concept of the controlling operation of theconventional air conditioner for railway vehicles shown in FIG. 71.

DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment

A first embodiment of the present invention will be explained withreference to FIG. 1 schematically showing a train car, a circuit diagramin FIG. 2 and a flowchart in FIG. 3. FIG. 1 schematically shows thestructure of a train car and the flow of data. In FIG. 1, the referencenumeral 5 represents a control switch portion by which a train operatorturns ON/OFF the air conditioner and sets the target temperature in thecar, 4 a control unit for controlling the air conditioner including aheating/cooling power correcting means, 6 a temperature detector fordetecting the air temperature in the car, and 9 an underfoot temperaturedetector provided in the vicinity of the floor of the car so as todetect the temperature in the vicinity of the feet of the passengersthere. The data on ON/OFF of the air conditioner and the targettemperature which has been set by the control switch portion 5, theoutput of the temperature detector 6, the output of the underfoottemperature detector 9, etc. are supplied to the control unit 4.

FIG. 2 is a circuit diagram of the control unit 4. The electric circuitof the control unit 4 is composed of an input circuit 41, a CPU 42, amemory 43 and an output circuit 44. The CPU 42 is provided with a targettemperature correcting portion 421 and an optimum heating/cooling powercalculator 422. The operation program of the heating/cooling powercorrecting means is stored in the memory 43 and calculated by the CPU42. The output of the control switch portion 5 provided in a trainoperator's compartment, the output of the temperature detector 6 and theoutput of the underfoot temperature detector 9 are input to the inputcircuit 41. A heating/cooling power controller 3 controls the power ofthe compressor in accordance with the output of the output circuit 44.

The operation of the air conditioner will be explained with reference tothe flowchart in FIG. 3. At step S11, the air conditioner of the trainis first turned ON by a train operator or the like, and the targettemperature is set at step S12. At step S13, a preset time for measuringthe temperature is allowed pass, and the temperature Ta of the air inthe car and the underfoot temperature Fa are detected at step S14. Atstep S15, the thermesthesia of the passengers is inferred from thevertical temperature difference fdT between the air temperature Ta inthe car and the underfoot temperature Fa. For example, when the verticaltemperature difference is large, it is inferred that the passengers feelcold, while when the vertical temperature difference is small, it isinferred that the passengers feel hot. The target temperature iscorrected from the result of the inference of the thermesthesia at stepS16. The correction value for the target temperature is calculated sothat the target temperature is lowered when the result of the inferenceof the thermesthesia is "hot", while the target temperature is raisedwhen the result is "cold", and the target temperature is not changedwhen the result is "medium". At step S17, the temperature difference dTbetween the air temperature in the car and the newly calculated targettemperature, and at step S18, the optimum cooling power is calculatedfrom the temperature difference dT. At step S19, the cooling operationis continued at the newly calculated cooling power.

In this way, the thermesthesia of the passengers is inferred from thetemperature difference between in the upper portion and the lowerportion of the car, and the correction value for the target temperatureis calculated so that the target temperature is lowered when the resultof the inference shows that the passenger feel hot while the targettemperature is raised when the result of the inference shows that thepassenger feel cold. Since the cooling operation is carried out whilecorrecting the target temperature, it is possible to constantly providea comfortable environment for the passengers.

Second Embodiment

A second embodiment of the present invention will be explained withreference to FIG. 4 schematically showing a train car, a circuit diagramin FIG. 5, a flowchart in FIG. 6, FIG. 7 showing the concept of a fuzzyrule for inferring the thermesthesia of the passengers, and FIG. 8showing the concept of the range of correction value.

FIG. 4 schematically shows the structure of a train car and the flow ofdata. In FIG. 4, the reference numeral 5 represents a control switchportion by which a train operator turns ON/OFF the air conditioner andsets the target temperature in the car, 4 a control unit for controllingthe air conditioner including a heating/cooling power correcting means,6 a temperature detector for detecting the temperature of the air in thecar, 9 an underfoot temperature detector provided in the vicinity of thefloor of the car so as to detect the temperature in the vicinity of thefeet of the passengers there and 10 a radiant heat quantity detector fordetecting the quantity of radiant heat generated by solar radiation orthe like. The data on ON/OFF of the air conditioner and the targettemperature which has been set by the control switch portion 5, theoutput of the temperature detector 6, the output of the underfoottemperature detector 9, the output of the radiant heat quantity detector10, etc. are supplied to the control unit 4.

FIG. 5 is a circuit diagram of the control unit 4. The electric circuitof the control unit 4 is composed of an input circuit 41, a CPU 42, amemory 43 and an output circuit 44. The CPU 42 is provided with a targettemperature correcting portion 421 and an optimum heating/cooling powercalculator 422. The operation program of the heating/cooling powercorrecting means is stored in the memory 43 and calculated by the CPU42. The output of the control switch portion 5 provided in a trainoperator's compartment, the output of the temperature detector 6, theoutput of the underfoot temperature detector 9 and the output of theradiant heat quantity detector 10 are input to the input circuit 41. Aheating/cooling power controller 3 controls the power of the compressorin accordance with the output of the output circuit 44.

The operation of the air conditioner will be explained with reference tothe flowchart in FIG. 6. At step S21, the air conditioner of the trainis first turned ON by a train operator or the like, and the targettemperature is set at step S22. At step S23, a preset time for measuringthe temperature is allowed to pass, and the air temperature Ta in thecar, the underfoot temperature Fa and the quantity Ra of radiant heatare detected at step S24. At step S25, the thermesthesia of thepassengers is inferred from the vertical temperature difference fdTbetween the air temperature Ta in the car and the underfoot temperatureFa and the quantity Ra of radiant heat in accordance with a fuzzy rulesuch as that shown in FIG. 7. According to the fuzzy rule shown in FIG.7, for example, when the vertical temperature difference is large andthe quantity of radiant heat is small, it is inferred that thepassengers feel cold, while when the vertical temperature difference issmall and the quantity of radiant heat is large, it is inferred that thepassengers feel hot. If the vertical temperature difference isintermediate between "large" and "medium" or "medium" and "small" or thequantity of radiant heat is intermediate between "small" and "medium" or"medium" and "large", the thermesthesia of the passengers is inferred tobe "slightly hot" or "slightly cold". The target temperature iscorrected from the result of the inference of the thermesthesia at stepS26. The correction value for the target temperature is calculated sothat the target temperature is lowered when the result of the inferenceof the thermesthesia is "hot", while the target temperature is raisedwhen the result is "cold", and the target temperature is not changedwhen the result is "medium", as shown in FIG. 8. At step S27, thetemperature difference dT between the temperature of the air in the carand the newly calculated target temperature, and at step S28, theoptimum cooling power is calculated from the temperature difference dT.At step S29, the cooling operation is continued at the newly calculatedcooling power.

In this way, the thermesthesia of the passengers is inferred from thetemperature difference between in the upper portion and the lowerportion of the car and the quantity of radiant heat, and the correctionvalue for the target temperature is calculated so that the targettemperature is lowered when the result of the inference shows that thepassenger feel hot while the target temperature is raised when theresult of the inference shows that the passenger feel cold. Since thecooling operation is carried out while correcting the targettemperature, it is possible to constantly provide a comfortableenvironment for the passengers.

Third Embodiment

A third embodiment of the present invention will be explained withreference to FIG. 9 schematically showing a train car, a circuit diagramin FIG. 10, a flowchart in FIG. 11, FIG. 12 showing the concept of afuzzy rule for inferring the thermesthesia of the passengers, and FIG.13 showing the concept of the range of correction value.

FIG. 9 schematically shows the structure of a train car and the flow ofdata. In FIG. 9, the reference numeral 5 represents a control switchportion by which a train operator turns ON/OFF the air conditioner andsets the target temperature in the car, 4 a control unit for controllingthe air conditioner including a heating/cooling power correcting means,6 a temperature detector for detecting the temperature of the air in thecar, 9 an underfoot temperature detector provided in the vicinity of thefloor of the car so as to detect the temperature in the vicinity of thefeet of the passengers there and 11 an anemometer for detecting thevelocity of the air current in the car. The data on ON/OFF of the airconditioner and the target temperature which has been set by the controlswitch portion 5, the output of the temperature detector 6, the outputof the underfoot temperature detector 9, the output of the anemometer11, etc. are supplied to the control unit 4.

FIG. 10 is a circuit diagram of the control unit 4. The electric circuitof the control unit 4 is composed of an input circuit 41, a CPU 42, amemory 43 and an output circuit 44. The CPU 42 is provided with a targettemperature correcting portion 421 and an optimum heating/cooling powercalculator 422. The operation program of the heating/cooling powercorrecting means is stored in the memory 43 and calculated by the CPU42. The output of the control switch portion 5 provided in a trainoperator's compartment, the output of the temperature detector 6, theoutput of the underfoot temperature detector 9 and the output of theanemometer 11 are input to the input circuit 41. A heating/cooling powercontroller 3 controls the power of the compressor in accordance with theoutput of the output circuit 44.

The operation of the air conditioner will be explained with reference tothe flowchart in FIG. 11. At step S31, the air conditioner of the trainis first turned ON by a train operator or the like, and the targettemperature is set at step S32. At step S33, the timing for measuringthe temperature is waited, and the temperature Ta of the air in the car,the underfoot temperature Fa and the velocity Va of the air current aredetected at step S34. At step S35, the thermesthesia of the passengersis inferred from the vertical temperature difference fdT between the airtemperature Ta in the car and the underfoot temperature Fa and thevelocity Va in accordance with a fuzzy rule such as that shown in FIG.12. According to the fuzzy rule shown in FIG. 12, for example, when thevertical temperature difference is large and velocity of the air currentis high, it is inferred that the passengers feel cold, while when thevertical temperature difference is small and the velocity of the aircurrent is low, it is inferred that the passengers feel hot. From thevertical temperature difference and the velocity of the air currentintermediate between "large" and "medium" or "medium" and "small" orintermediate between "high" and "medium" or "medium" and "low", thelevel of the thermesthesia of the passengers is also inferred. Thetarget temperature is corrected from the result of the inference of thethermesthesia in accordance with the level of the themesthesia, as shownin FIG. 13, at step S36. At step S37, the temperature difference dTbetween the temperature of the air in the car and the newly calculatedtarget temperature, and at step S38, the optimum cooling power iscalculated from the temperature difference dT. At step S39, the coolingoperation is continued at the newly calculated cooling power.

In this way, the thermesthesia of the passengers is inferred from thetemperature difference between in the upper portion and the lowerportion of the car and the velocity of the air current in the car, andthe correction value for the target temperature is calculated so thatthe target temperature is lowered when the result of the inference showsthat the passenger feel hot while the target temperature is raised whenthe result of the inference shows that the passenger feel cold. Sincethe cooling operation is carried out while correcting the targettemperature, it is possible to constantly provide a comfortableenvironment for the passengers.

Fourth Embodiment

A fourth embodiment of the present invention will be explained withreference to FIG. 14 schematically showing a train car, a circuitdiagram in FIG. 15, a flowchart in FIG. 16, and FIG. 17 showing theconcept of the correction of a target temperature in accordance with ahumidity.

FIG. 14 schematically shows the structure of a train car and the flow ofdata. In FIG. 14, the reference numeral 5 represents a control switchportion by which a train operator turns ON/OFF the air conditioner andsets the target temperature in the car, 4 a control unit for controllingthe air conditioner including a target temperature correcting means forcorrecting the target temperature in accordance with a humidity, 6 atemperature detector for detecting the temperature of the air in thecar, 9 an underfoot temperature detector provided in the vicinity of thefloor of the car so as to detect the temperature in the vicinity of thefeet of the passengers there, 10 a radiant heat quantity detector fordetecting the quantity of radiant heat generated by solar radiation orthe like, and 12 a hygrometer for detecting the relative humidity. Thedata on ON/OFF of the air conditioner and the target temperature whichhas been set by the control switch portion 5, the output of thetemperature detector 6, the output of the underfoot temperature detector9, the output of the radiant heat quantity detector 10, the output ofthe hygrometer 12, etc. are supplied to the control unit 4.

FIG. 12 is a circuit diagram of the control unit 4. The electric circuitof the control unit 4 is composed of an input circuit 41, a CPU 42, amemory 43 and an output circuit 44. The CPU 42 is provided with a targettemperature correcting portion 421 and an optimum heating/cooling powercalculator 422. The operation program of the target temperaturecorrecting means is stored in the memory 43 and calculated by the CPU42. The output of the control switch portion 5 provided in a trainoperator's compartment, the output of the temperature detector 6, theoutput of the underfoot temperature detector 9, the output of theradiant heat quantity detector 10 and the output of the hygrometer 12are input to the input circuit 41. A heating/cooling power controller 3controls the power of the compressor in accordance with the output ofthe output circuit 44.

The operation of the air conditioner will be explained with reference tothe flowchart in FIG. 16. At step S41, the air conditioner of the trainis first turned ON by a train operator or the like, and the targettemperature is set at step S42. At step S43, a preset time for measuringthe temperature is allowing to pass, and the air temperature Ta in thecar, the underfoot temperature Fa and the quantity Ra of radiant heatand the relative humidity Ha are detected at step S44. At step S45, thethermesthesia of the passengers is inferred from the verticaltemperature difference fdT between the temperature Ta of the air in thecar, the underfoot temperature Fa and the quantity Ra of radiant heat.The target temperature is corrected from the result of the inference ofthe thermesthesia at step S46. At step S47, the target temperaturecorrecting means calculates the correction value for the targettemperature in accordance with the detected relative humidity so thatthe target temperature is lowered when the humidity is high, while thetarget temperature is raised when the humidity is low, as shown in FIG.17. In this way, the target temperature which has been corrected inaccordance with the result of the inference of the thermesthesia isfurther corrected by the correction value. At step S48, the temperaturedifference dT between the temperature of the air in the car and thenewly calculated target temperature is calculated. At step S49, theoptimum cooling power is calculated and the cooling operation iscontinued at the newly calculated cooling power at step 50.

In this way, the thermesthesia of the passengers is inferred from thetemperature difference between in the upper portion and the lowerportion of the car and the quantity of radiant heat, and the correctionvalue for the target temperature is calculated. The target temperatureis further corrected in accordance with the relative humidity. Since thecooling operation is carried out while correcting the target temperaturein correspondence with the thermesthesia of the passengers, it ispossible to constantly provide a comfortable environment for thepassengers.

Fifth Embodiment

A fifth embodiment of the present invention will be explained withreference to FIG. 18 schematically showing a train car, a circuitdiagram in FIG. 19, a flowchart in FIG. 20, and FIG. 17 showing theconcept of the correction of a target temperature in accordance with ahumidity.

FIG. 18 schematically shows the structure of a train car and the flow ofdata. In FIG. 18, the reference numeral 5 represents a control switchportion by which a train operator turns ON/OFF the air conditioner andsets the target temperature in the car, 4 a control unit for controllingthe air conditioner including a target temperature correcting means forcorrecting the target temperature in accordance with a humidity, 6 atemperature detector for detecting the air temperature in the car, 9 anunderfoot temperature detector provided in the vicinity of the floor ofthe car so as to detect the temperature in the vicinity of the feet ofthe passengers there, 11 an anemometer for detecting the velocity of theair current in the car and 12 a hygrometer for detecting the relativehumidity. The data on ON/OFF of the air conditioner and the targettemperature which has been set by the control switch portion 5, theoutput of the temperature detector 6, the output of the underfoottemperature detector 9, the output of the anemometer 11, the output ofthe hygrometer 12, etc. are supplied to the control unit 4.

FIG. 19 is a circuit diagram of the control unit 4. The electric circuitof the control unit 4 is composed of an input circuit 41, a CPU 42, amemory 43 and an output circuit 44. The CPU 42 is provided with a targettemperature correcting portion 421 and an optimum heating/cooling powercalculator 422. The operation program of the target temperaturecorrecting means is stored in the memory 43 and calculated by the CPU42. The output of the control switch portion 5 provided in a trainoperator's compartment, the output of the temperature detector 6, theoutput of the underfoot temperature detector 9, the output of theanemometer 11 and the output of the hygrometer 12 are input to the inputcircuit 41. A heating/cooling power controller 3 controls the power ofthe compressor in accordance with the output of the output circuit 44.

The operation of the air conditioner will be explained with reference tothe flowchart in FIG. 20. At step S51, the air conditioner of the trainis first turned ON by a train operator or the like, and the targettemperature is set at step S42. At step S53, a present time formeasuring the temperature is allowed to pass, and the air temperature Tain the car, the underfoot temperature Fa, the velocity Va of the aircurrent and the relative humidity Ha are detected at step S44. At stepS55, the thermesthesia of the passengers is inferred from the verticaltemperature difference fdT between the temperature Ta of the air in thecar and the underfoot temperature Fa and the velocity Va of the aircurrent. The target temperature is corrected from the result of theinference of the thermesthesia at step S56. At step S57, the targettemperature correcting means calculates the correction value for thetarget temperature in accordance with the detected relative humidity sothat the target temperature is lowered when the humidity is high, whilethe target temperature is raised when the humidity is low, as shown inFIG. 17. In this way, the target temperature which has been corrected inaccordance with the result of the inference of the thermesthesia isfurther corrected by the correction value. At step S58, the temperaturedifference dT between the air temperature in the car and the newlycalculated target temperature is calculated. At step S59, the optimumcooling power is calculated and the cooling operation is continued atthe newly calculated cooling power at step 60.

In this way, the thermesthesia of the passengers is inferred from thetemperature difference between in the upper portion and the lowerportion of the car and the velocity of the air current, and thecorrection value for the target temperature is calculated. The targettemperature is further corrected in accordance with the relativehumidity. Since the cooling operation is carried out while correctingthe target temperature in correspondence with the thermesthesia of thepassengers, it is possible to constantly provide a comfortableenvironment for the passengers.

The schematic view of a train car in FIG. 21 and the circuit diagram inFIG. 22 show an example of the control of the power of an airconditioner by the use of a temperature detector 6 for detecting the airtemperature in a car and at least one cooling power correcting valuedata detector 100.

FIG. 21 schematically shows the structure of a train car and the flow ofdata. In FIG. 21, the reference numeral 100 represents a cooling powercorrecting value data detector 100 provided separately from thetemperature detector 6 for detecting the temperature of the air in acar, and 4 a control unit for controlling the air conditioner includinga heating/cooling power correcting means. Various data detected by thecooling power correcting value data detector 100 are supplied to thecontrol unit 4.

FIG. 22 is a circuit diagram of the control unit 4. The electric circuitof the control unit 4 is composed of an input circuit 41, a CPU 42, amemory 43 and an output circuit 44. The CPU 42 is provided with anoptimum heating/cooling power calculator 422 and a heating/cooling powercorrecting means 423. The operation program of the heating/cooling powercorrecting means is stored in the memory 43 and calculated by the CPU42. The output of the control switch portion 5 provided in a trainoperator's compartment, the output of the temperature detector 6 and theoutput of the cooling power correcting value data detector 100 are inputto the input circuit 41. A heating/cooling power controller 3 controlsthe power of the compressor in accordance with the output of the outputcircuit 44. Concrete examples of the cooling power correcting value datadetector 100 will be explained in the following embodiments.

Sixth Embodiment

A sixth embodiment of the present invention will be explained withreference to FIGS. 23 to 25. FIG. 23 schematically shows a train car,FIG. 24 is a circuit diagram of the sixth embodiment and FIG. 25 is aflowchart of the controlling operation of the sixth embodiment. FIG. 23schematically shows the structure of a train car and the flow of data.In FIG. 23, the cooling power correcting value data detector 100 shownin FIG. 21 is shown as a radiant heat quantity detector 10 for detectingthe quantity of radiant heat. The quantity of radiant heat detected bythe radiant heat quantity detector is supplied to the control unit 4 ofthe air conditioner.

FIG. 24 is a circuit diagram of the control unit 4. The cooling powercorrecting value data detector 100 shown in FIG. 22 is shown as theradiant heat quantity detector 10. The operation program of theheating/cooling power correcting means is stored in the memory 43 andcalculated by the CPU 42.

The operation of the air conditioner will now be explained withreference to the flowchart in FIG. 25. At step S61, the air conditionerof the train is first turned ON by a train operator or the like, and thetarget temperature is set at step S62. At step S63, a preset time formeasuring the temperature is allowed pass, and the temperature Ta of theair in the car and the quantity Ra of radiant heat are detected at stepS64. At step S65, the temperature difference dT between the targettemperature and the temperature Ta of the air in the car is obtained.The correction value for the heating/cooling power is inferred from thetemperature difference dT between the target temperature and thetemperature of the air in the car in accordance with a fuzzy rule sothat the air temperature in the car is equal to the target temperature,and the optimum cooling power is calculated at step 66. The next step 67is a routine showing the heating/cooling power correcting means. Theheating/cooling power is corrected in accordance with the detectedquantity Ra of radiant heat so that when the output of the optimumheating/cooling power calculator indicates that the cooling power isincreased, the cooling power is increased to a slightly larger valuethan the calculated value if the quantity of radiant heat is large,while the cooling power is increased to a slightly smaller value thanthe calculated value if the quantity of radiant heat is small. On theother hand, when the output of the optimum heating/cooling powercalculator indicates that the cooling power is reduced, the coolingpower is reduced to a slightly smaller value than the calculated valueif the quantity of radiant heat is large, while the cooling power isreduced to a slightly larger value than the calculated value if thequantity of radiant heat is small. At step S68, the cooling operation iscontinued at the newly corrected cooling power.

Seventh Embodiment

A seventh embodiment of the present invention will be explained withreference to FIGS. 26 schematically showing a train car and a circuitdiagram shown in FIG. 27. FIG. 26 schematically shows the structure of atrain car and the flow of data. In FIG. 26, the cooling power correctingvalue data detector 100 shown in FIG. 21 is shown as an outdoor airtemperature detector 13. The reference numeral 4 denotes a control unitof the air conditioner provided with a heating/cooling power determiningmeans including a heating/cooling power correcting means. Thetemperature of the out door detected by the temperature of the out doordetector 13 is supplied to the control unit 4.

FIG. 27 is a circuit diagram of the control unit 4. The electric circuitof the control unit 4 is composed of an input circuit 41, a CPU 42, amemory 43 and an output circuit 44. The CPU 42 is provided with anoptimum heating/cooling power calculator 422 and a heating/cooling powercorrecting means 423. The operation program of the heating/cooling powercorrecting means is stored in the memory 43 and calculated by the CPU42. The output of the control switch portion 5 provided in a trainoperator's compartment, the output of the temperature detector 6 and theoutput of the outside air temperature detector 13 are input to the inputcircuit 41. A heating/cooling power controller 3 controls the power ofthe compressor in accordance with the output of the output circuit 44.

The operation of the air conditioner will now be explained withreference to the flowchart in FIG. 28. At step S71, the air conditionerof the train is first turned ON by a train operator or the like, and thetarget temperature is set at step S72. At step S73, the timing formeasuring the temperature is waited, and the air temperature Ta in thecar and the outside air temperature Tg are detected at step S74. At stepS75, the temperature difference dT between the target temperature andthe air temperature in the car is obtained.

The correction value for the heating/cooling power is inferred from thetemperature difference dT between the target temperature and the airtemperature in the car in accordance with a fuzzy rule so that the airtemperature in the car is equal to the target temperature, and theoptimum cooling power is calculated at step 76. The next step 77 is aroutine showing the heating/cooling power correcting means. Theheating/cooling power is corrected in accordance with the detectedtemperature Tg of the outside air so that when the output of the optimumheating/cooling power calculator indicates that the cooling power isincreased, the cooling power is increased to a slightly larger valuethan the calculated value if the temperature of the outside air is high,while the cooling power is increased to a slightly smaller value thanthe calculated value if the temperature of the outside air is low. Onthe other hand, when the output of the optimum heating/cooling powercalculator indicates that the cooling power is reduced, the coolingpower is reduced to a slightly smaller value than the calculated valueif the temperature of the outside air is high, while the cooling poweris reduced to a slightly larger value than the calculated value if theoutside air temperature is low. At step S78, the cooling operation iscontinued at the newly corrected cooling power.

Eighth Embodiment

An eighth embodiment of the present invention will be explained withreference to FIGS. 29 to 31. FIG. 29 schematically shows a train car,FIG. 30 is a circuit diagram of the eight embodiment and FIG. 31 is aflowchart of the controlling operation of the eighth embodiment. FIG. 29schematically shows the structure of a train car and the flow of data.In FIG. 29, the cooling power correcting value data detector 100 shownin FIG. 21 is shown as a passenger number detector 14 for detecting thenumber of passengers. The passenger number detector 14 obtains the totalweight of the car, for example, on the basis of the amount ofcontraction of the spring of a car suspension device and detects thenumber of passengers from the total weight. The reference numeral 4denotes a control unit of the air conditioner provided with aheating/cooling power determining means including a heating/coolingpower correcting means. The number of passengers detected by thepassenger number detector 14

FIG. 30 is a circuit diagram of the control unit 4. The electric circuitof the control unit 4 is composed of an input circuit 41, a CPU 42, amemory 43 and an output circuit 44. The CPU 42 is provided with anoptimum heating/cooling power calculator 422 and a heating/cooling powercorrecting means 423. The operation program of the heating/cooling powercorrecting means is stored in the memory 43 and calculated by the CPU42. The output of the control switch portion 5 provided in a trainoperator's compartment, the output of the temperature detector 6 and theoutput of the passenger number detector 14 are input to the inputcircuit 41. A heating/cooling power controller 3 controls the power ofthe compressor in accordance with the output of the output circuit 44.

The operation of the air conditioner will now be explained withreference to the flowchart in FIG. 31. At step S81, the air conditionerof the train is first turned ON by a train operator or the like, and thetarget temperature is set at step S82. At step S83, the timing formeasuring the temperature is waited, and the temperature Ta of the airin the car and the number Tp of passengers are detected at step S84. Atstep S85, the temperature difference dT between the target temperatureand the air temperature in the car is obtained.

The correction value for the heating/cooling power is inferred from thetemperature difference dT between the target temperature and thetemperature of the air in the car in accordance with a fuzzy rule, andthe optimum cooling power is calculated at step 86. The next step 87 isa routine showing the heating/cooling power correcting means. Theheating/cooling power is corrected in accordance with the detectednumber Tp of passengers so that when the output of the optimumheating/cooling power calculator indicates that the cooling power isincreased, the cooling power is increased to a slightly larger valuethan the calculated value if the number of passengers is large, whilethe cooling power is increased to a slightly smaller value than thecalculated value if the number of passengers is small. On the otherhand, when the output of the optimum heating/cooling power calculatorindicates that the cooling power is reduced, the cooling power isreduced to a slightly smaller value than the calculated value if thenumber of passengers is small, while the cooling power is reduced to aslightly larger value than the calculated value if the number ofpassengers is large. At step S88, the cooling operation is continued atthe newly corrected cooling power.

Ninth Embodiment

A ninth embodiment of the present invention will be explained withreference to FIGS. 32 to 34. FIG. 32 schematically shows a train car,FIG. 33 is a circuit diagram of the ninth embodiment and FIG. 34 is aflowchart of the controlling operation of the ninth embodiment. FIG. 32schematically shows the structure of a train car and the flow of data.In FIG. 32, the cooling power correcting value data detector 100 shownin FIG. 21 is shown as an outside air temperature detector 13 and apassenger number detector 14. The reference numeral 4 denotes a controlunit of the air conditioner provided with a heating/cooling powerdetermining means including a heating/cooling power correcting means.The outside air temperature and the number of passengers detected by theoutside air temperature detector 13 and the passenger number detector14, respectively, are supplied to the control unit 4.

FIG. 33 is a circuit diagram of the control unit 4. The electric circuitof the control unit 4 is composed of an input circuit 41, a CPU 42, amemory 43 and an output circuit 44. The CPU 42 is provided with anoptimum heating/cooling power calculator 422 and a heating/cooling powercorrecting means 423. The operation program of the heating/cooling powercorrecting means is stored in the memory 43 and calculated by the CPU42. The output of the control switch portion 5 provided in a trainoperator's compartment, the output of the temperature detector 6, theoutput of the outside air temperature detector 13 and the output of thepassenger number detector 14 are input to the input circuit 41. Aninverter 3 controls the power of the compressor in accordance with theoutput of the output circuit 44.

The operation of the air conditioner will now be explained withreference to the flowchart in FIG. 34. At step S91, the air conditionerof the train is first turned ON by a train operator or the like, and thetarget temperature is set at step S92. At step S93, the timing formeasuring the temperature is waited, and the air temperature Ta in thecar, the outside air temperature Tg and the number Tp of passengers aredetected at step S94. At step S95, the temperature difference dT betweenthe target temperature and the air temperature in the car is obtained.

The correction value for the heating/cooling power is inferred from thetemperature difference dT between the target temperature and the airtemperature in the car in accordance with a fuzzy rule so that thetemperature of the air in the car is equal to the target temperature,and the optimum cooling power is calculated at step 96. The next step 97is a routine showing the heating/cooling power correcting means. Theload in the heating/cooling system is obtained from the detectedtemperature Tg of the outside air and number Tp of passengers inaccordance with a fuzzy rule in such a manner that the load is "large"when the temperature of the outside air is high and the number ofpassengers is large, that the load is "small" when the temperature ofthe outside air is low and the number of passengers is small, and thatthe load is "medium" when the temperature of the outside air is high andthe number of passengers is small. When the output of the optimumheating/cooling power calculator indicates that the cooling power isincreased due to the load in the heating/cooling system, the coolingpower is corrected so as to be increased to a slightly larger value thanthe calculated value if the load is large and to be increased to aslightly smaller value than the calculated value if the load is small.On the other hand, when the output of the optimum heating/cooling powercalculator indicates that the cooling power is reduced, the coolingpower is corrected so as to be reduced to a slightly larger value thanthe calculated value if the load is large and to be reduced to aslightly smaller value than the calculated value if the load is small.At step S98, the cooling operation is continued at the newly correctedcooling power.

Tenth Embodiment

A tenth embodiment of the present invention will be explained withreference to FIGS. 35 to 38. FIG. 35 schematically shows a train car,FIG. 36 is a circuit diagram of the tenth embodiment, FIG. 37 is aflowchart of the controlling operation of the tenth embodiment, FIG. 38shows the concept of a door coefficient and FIG. 39 shows the concept ofthe controlling operation of the tenth embodiment. FIG. 35 schematicallyshows the structure of a train car and the flow of data. In FIG. 35, thereference numeral 5 represents a control switch portion by which a trainoperator turns ON/OFF the air conditioner, 15 a door switch portion foropening and closing the doors, and 4 a control unit for controlling theair conditioner including a heating/cooling power correcting means. Thedata on ON/OFF of the air conditioner and the opening of the doors aresupplied to the control unit 4.

FIG. 36 is a circuit diagram of the control unit 4. The electric circuitof the control unit 4 is composed of an input circuit 41, a CPU 42, amemory 43 and an output circuit 44. The CPU 42 is provided with anoptimum heating/cooling power calculator 422 and a heating/cooling powercorrecting means 423. The operation program of the heating/cooling powercorrecting means is stored in the memory 43 and calculated by the CPU42. The output of the control switch portion 5 provided in a trainoperator's compartment and the output of a temperature detector 6 areinput to the input circuit 41. A heating/cooling power controller 3controls the power of the compressor in accordance with the output ofthe output circuit 44.

The operation of the air conditioner will now be explained withreference to the flowchart in FIG. 37. At step S101, the air conditionerof the train is first turned ON by a train operator or the like, and thetarget temperature is set at step S102. At step S103, the timing formeasuring the temperature is waited, and the temperature Ta of the airin the car, the temperature Tg of the outside air and the number Tp ofpassengers are detected at step S104. At step S105, the temperaturedifference dT between the target temperature and the air temperature inthe car is obtained.

The correction value for the heating/cooling power is inferred from thetemperature difference dT between the target temperature and thetemperature of the air in the car in accordance with a fuzzy rule sothat the temperature of the air in the car is equal to the targettemperature, and the optimum cooling power is calculated at step 106.The next step 107 is a routine showing the heating/cooling powercorrecting means. A door coefficient is obtained from the time elapsedfrom the opening operation of the doors in accordance with the conceptof a door coefficient shown in FIG. 38. The correction value ismultiplied by the door coefficient so as to obtain a new correctionvalue. In this case, however, if a predetermined time (Ts) has elapsedfrom the opening operation of the doors, the door coefficient is set at"1" and the correction value is not changed. At step S108, the coolingpower is corrected by the newly-obtained correction value, and at step109 the cooling operation is continued at the newly corrected coolingpower.

In the above-described first to tenth embodiments, the air conditioneris controlled by proportional control which is carried out bycalculating the required cooling power from the temperature differencebetween the current air temperature in the car and the targettemperature. It is also possible to control the air conditioner in anyof the first to tenth embodiments by PID control shown in JapaneseUtility Model Laid-Open No. Hei 2-41037. That is, the air conditionercontrolled on the basis of the temperature difference between thecurrent air temperature in the car and the target temperature and thedata on how long this temperature difference has lasted.

Embodiments controlled by PID control will be explained in thefollowing.

Eleventh Embodiment

An eleventh embodiment of the present invention will be explained withreference to FIG. 1 schematically showing a train car, a circuit diagramin FIG. 39 and a flowchart in FIG. 40. FIG. 1 schematically shows thestructure of a train car and the flow of data. In FIG. 1, the referencenumeral 5 represents a control switch portion by which a train operatorturns ON/OFF the air conditioner and sets the target temperature in thecar, 4 a control unit for controlling the air conditioner including aheating/cooling power correcting means, 6 a temperature detector fordetecting the temperature of the air in the car, and 9 an underfoottemperature detector provided in the vicinity of the floor of the car soas to detect the temperature in the vicinity of the feet of thepassengers there. The data on ON/OFF of the air conditioner and thetarget temperature which has been set by the control switch portion 5,the output of the temperature detector 6, the output of the underfoottemperature detector 9, etc. are supplied to the control unit 4.

FIG. 39 is a circuit diagram of the control unit 4. The electric circuitof the control unit 4 is composed of an input circuit 41, a CPU 42, amemory 43 and an output circuit 44. The CPU 42 is provided with a targettemperature correcting portion 421 and an optimum heating/cooling powercalculator 422. The memory 43 has a region 431 for storing a precedentlycalculated temperature difference between the target temperature and thetemperature of the air in the car. The operation program of theheating/cooling power correcting means is stored in the memory 43 andcalculated by the CPU 42. The output of the control switch portion 5provided in a train operator's compartment, the output of thetemperature detector 6 and the output of the underfoot temperaturedetector 9 are input to the input circuit 41. A heating/cooling powercontroller 3 controls the power of the compressor in accordance with theoutput of the output circuit 44.

The operation of the air conditioner will be explained with reference tothe flowchart in FIG. 39. At step S111, the air conditioner of the trainis first turned ON by a train operator or the like, and the targettemperature is set at step S112. At step S113, the timing for measuringthe temperature is waited, and the temperature Ta of the air in the carand the underfoot temperature Fa are detected at step S114. At stepS115, the thermesthesia of the passengers is inferred from the verticaltemperature difference fdT between the temperature Ta of the air in thecar and the underfoot temperature Fa. For example, when the verticaltemperature difference is large, it is inferred that the passengers feelcold, while when the vertical temperature difference is small, it isinferred that the passengers feel hot. The target temperature iscorrected from the result of the inference of the thermesthesia at stepS116. The correction value for the target temperature is calculated sothat the target temperature is lowered when the result of the inferenceof the thermesthesia is "hot", while the target temperature is raisedwhen the result is "cold", and the target temperature is not changedwhen the result is "medium". At step S117, the temperature difference dTbetween the temperature of the air in the car and the newly calculatedtarget temperature. At step S118, judgement is made as to whether or notthe current measurement is a first measurement. If this is a firstmeasurement, this temperature difference is stored in the memory 43 as aprecedent temperature difference dTs at step 122. On the other hand, ifthis is judged to be a second or later measurement at step S118, thevariance St of temperature difference with time, which is the differencebetween the precedent temperature difference dTs and the currenttemperature difference dT, is obtained at step S119. From the varianceof temperature difference with time, whether the temperature in the caris stable or it has changed in a short time is grasped and thecorrection value for the cooling power is obtained. The current coolingpower is corrected by the thus-obtained correction value at step S120.At step S121, the cooling operation is continued at the newly calculatedcooling power.

In this way, the thermesthesia of the passengers is inferred from thetemperature difference between in the upper portion and the lowerportion of the car, and the correction value for the target temperatureis calculated so that the target temperature is lowered when the resultof the inference shows that the passenger feel hot while the targettemperature is raised when the result of the inference shows that thepassenger feel cold. Since the cooling operation is carried out whilecorrecting the target temperature, it is possible to constantly providea comfortable environment for the passengers.

Twelfth Embodiment

A twelfth embodiment of the present invention will be explained withreference to FIG. 4 schematically showing a train car, a circuit diagramin FIG. 41, a flowchart in FIG. 42, FIG. 7 showing the concept of afuzzy rule for inferring the thermesthesia of the passengers, and FIG. 8showing the concept of the range of correction value.

FIG. 4 schematically shows the structure of a train car and the flow ofdata. In FIG. 4, the reference numeral 5 represents a control switchportion by which a train operator turns ON/OFF the air conditioner andsets the target temperature in the car, 4 a control unit for controllingthe air conditioner including a heating/cooling power correcting means,6 a temperature detector for detecting the air temperature in the car, 9an underfoot temperature detector provided in the vicinity of the floorof the car so as to detect the temperature in the vicinity of the feetof the passengers there and 10 a radiant heat quantity detector fordetecting the quantity of radiant heat generated by solar radiation orthe like. The data on ON/OFF of the air conditioner and the targettemperature which has been set by the control switch portion 5, theoutput of the temperature detector 6, the output of the underfoottemperature detector 9, the output of the radiant heat quantity detector10, etc. are supplied to the control unit 4.

FIG. 41 is a circuit diagram of the control unit 4. The electric circuitof the control unit 4 is composed of an input circuit 41, a CPU 42, amemory 43 and an output circuit 44. The CPU 42 is provided with a targettemperature correcting portion 421 and an optimum heating/cooling powercalculator 422. The memory 43 has a region 431 for storing a precedentlycalculated temperature difference between the target temperature and thetemperature of the air in the car. The operation program of theheating/cooling power correcting means is stored in the memory 43 andcalculated by the CPU 42. The output of the control switch portion 5provided in a train operator's compartment, the output of thetemperature detector 6, the output of the underfoot temperature detector9 and the output of the radiant heat quantity detector 10 are input tothe input circuit 41. A heating/cooling power controller 3 controls thepower of the compressor in accordance with the output of the outputcircuit 44.

The operation of the air conditioner will be explained with reference tothe flowchart in FIG. 42. At step S131, the air conditioner of the trainis first turned ON by a train operator or the like, and the targettemperature is set at step S132. At step S133, the timing for measuringthe temperature is waited, and the air temperature Ta in the car, theunderfoot temperature Fa and the quantity Ra of radiant heat aredetected at step S134. At step S135, the thermesthesia of the passengersis inferred from the vertical temperature difference fdT between thetemperature Ta of the air in the car and the underfoot temperature Faand the quantity Ra of radiant heat in accordance with a fuzzy rule suchas that shown in FIG. 7. According to the fuzzy rule shown in FIG. 7,for example, when the vertical temperature difference is large and thequantity of radiant heat is small, it is inferred that the passengersfeel cold, while when the vertical temperature difference is small andthe quantity of radiant heat is large, it is inferred that thepassengers feel hot. If the vertical temperature difference isintermediate between "large" and "medium" or "medium" and "small" or thequantity of radiant heat is intermediate between "small" and "medium" or"medium" and "large", the thermesthesia of the passengers is inferred tobe "slightly hot" or "slightly cold". The target temperature iscorrected from the result of the inference of the thermesthesia at stepS136. The correction value for the target temperature is calculated sothat the target temperature is lowered when the result of the inferenceof the thermesthesia is "hot", while the target temperature is raisedwhen the result is "cold", and the target temperature is not changedwhen the result is "medium", as shown in FIG. 8. At step S138, judgementis made as to whether or not the current measurement is a firstmeasurement. If this is a first measurement, this temperature differenceis stored in the memory 43 as a precedent temperature difference dTs atstep 142. On the other hand, if this is judged to be a second or latermeasurement at step S138, the variance St of temperature difference withtime, which is the difference between the precedent temperaturedifference dTs and the current temperature difference dT, is obtained atstep S139. From the variance of temperature difference with time,whether the temperature in the car is stable or it has changed in ashort time is grasped and the correction value for the cooling power isobtained. The current cooling power is corrected by the thus-obtainedcorrection value at step S140. At step S141, the cooling operation iscontinued at the newly calculated cooling power. The newly calculatedtemperature difference is stored in the memory 431 as a precedenttemperature difference dTs at step 142.

In this way, the thermesthesia of the passengers is inferred from thetemperature difference between in the upper portion and the lowerportion of the car and the quantity of radiant heat, and the correctionvalue for the target temperature is calculated so that the targettemperature is lowered when the result of the inference shows that thepassenger feel hot while the target temperature is raised when theresult of the inference shows that the passenger feel cold. Since thecooling operation is carried out while correcting the targettemperature, it is possible to constantly provide a comfortableenvironment for the passengers.

Thirteenth Embodiment

A thirteenth embodiment of the present invention will be explained withreference to FIG. 9 schematically showing a train car, a circuit diagramin FIG. 43, a flowchart in FIG. 44, FIG. 12 showing the concept of afuzzy rule for inferring the thermesthesia of the passengers, and FIG.13 showing the concept of the range of correction value.

FIG. 9 schematically shows the structure of a train car and the flow ofdata. In FIG. 9, the reference numeral 5 represents a control switchportion by which a train operator turns ON/OFF the air conditioner andsets the target temperature in the car, 4 a control unit for controllingthe air conditioner including a heating/cooling power correcting means,6 a temperature detector for detecting the air temperature in the car, 9an underfoot temperature detector provided in the vicinity of the floorof the car so as to detect the temperature in the vicinity of the feetof the passengers there and 11 an anemometer for detecting the velocityof the air current in the car. The data on ON/OFF of the air conditionerand the target temperature which has been set by the control switchportion 5, the output of the temperature detector 6, the output of theunderfoot temperature detector 9, the output of the anemometer 11, etc.are supplied to the control unit 4.

FIG. 43 is a circuit diagram of the control unit 4. The electric circuitof the control unit 4 is composed of an input circuit 41, a CPU 42, amemory 43 and an output circuit 44. The CPU 42 is provided with a targettemperature correcting portion 421 and an optimum heating/cooling powercalculator 422. The memory 43 has a region 431 for storing a precedentlycalculated temperature difference between the target temperature and thetemperature of the air in the car. The operation program of theheating/cooling power correcting means is stored in the memory 43 andcalculated by the CPU 42. The output of the control switch portion 5provided in a train operator's compartment, the output of thetemperature detector 6, the output of the underfoot temperature detector9 and the output of the anemometer 11 are input to the input circuit 41.A heating/cooling power controller 3 controls the power of thecompressor in accordance with the output of the output circuit 44.

The operation of the air conditioner will be explained with reference tothe flowchart in FIG. 44. At step S151, the air conditioner of the trainis first turned ON by a train operator or the like, and the targettemperature is set at step S152. At step S153, the timing for measuringthe temperature is waited, and the temperature Ta of the air in the car,the underfoot temperature Fa and the velocity Va of the air current aredetected at step S154. At step S155, the thermesthesia of the passengersis inferred from the vertical temperature difference fdT between the airtemperature Ta in the car and the underfoot temperature Fa and thevelocity Va in accordance with a fuzzy rule such as that shown in FIG.12. According to the fuzzy rule shown in FIG. 12, for example, when thevertical temperature difference is large and velocity of the air currentis high, it is inferred that the passengers feel cold, while when thevertical temperature difference is small and the velocity of the aircurrent is low, it is inferred that the passengers feel hot. From thevertical temperature difference and the velocity of the air currentintermediate between "large" and "medium" or "medium" and "small" orintermediate between "high" and "medium" or "medium" and "low", thelevel of the thermesthesia of the passengers is also inferred. From theresult of the inference of the thermesthesia, the correction value forthe target temperature is calculated in accordance with the level of thethermesthesia, as shown in FIG. 13. For example, the target temperatureis lowered when the result of the inference is "hot", the targettemperature is raised when the result of the inference is "cold" and thetarget temperature is not changed when the result of the inference is"medium". At step S156, the target temperature is corrected by thecalculated correction value. At step S158, judgement is made as towhether or not the current measurement is a first measurement. If thisis a first measurement, this temperature difference is stored in thememory 43 as a precedent temperature difference dTs at step 162. On theother hand, if this is judged to be a second or later measurement atstep S158, the variance St of temperature difference with time, which isthe difference between the precedent temperature difference dTs and thecurrent temperature difference dT, is obtained at step S159. From thevariance of temperature difference with time, whether the temperature inthe car is stable or it has changed in a short time is grasped and thecorrection value for the cooling power is obtained. The current coolingpower is corrected by the thus-obtained correction value at step S160.At step S161, the cooling operation is continued at the newly calculatedcooling power.

In this way, the thermesthesia of the passengers is inferred from thetemperature difference between in the upper portion and the lowerportion of the car and the velocity of the air current in the car, andthe correction value for the target temperature is calculated so thatthe target temperature is lowered when the result of the inference showsthat the passenger feel hot while the target temperature is raised whenthe result of the inference shows that the passenger feel cold. Sincethe cooling operation is carried out while correcting the targettemperature, it is possible to constantly provide a comfortableenvironment for the passengers.

Fourteenth Embodiment

A fourteenth embodiment of the present invention will be explained withreference to FIG. 14 schematically showing a train car, a circuitdiagram in FIG. 45, a flowchart in FIG. 46, and FIG. 17 showing theconcept of the correction of a target temperature in accordance with ahumidity.

FIG. 14 schematically shows the structure of a train car and the flow ofdata. In FIG. 14, the reference numeral 5 represents a control switchportion by which a train operator turns ON/OFF the air conditioner andsets the target temperature in the car, 4 a control unit for controllingthe air conditioner including a target temperature correcting means forcorrecting the target temperature in accordance with a humidity, 6 atemperature detector for detecting the temperature of the air in thecar, 9 an underfoot temperature detector provided in the vicinity of thefloor of the car so as to detect the temperature in the vicinity of thefeet of the passengers there, 10 a radiant heat quantity detector fordetecting the quantity of radiant heat generated by solar radiation orthe like, and 12 a hygrometer for detecting the relative humidity. Thedata on ON/OFF of the air conditioner and the target temperature whichhas been set by the control switch portion 5, the output of thetemperature detector 6, the output of the underfoot temperature detector9, the output of the radiant heat quantity detector 10, the output ofthe hygrometer 12, etc. are supplied to the control unit 4.

FIG. 45 is a circuit diagram of the control unit 4. The electric circuitof the control unit 4 is composed of an input circuit 41, a CPU 42, amemory 43 and an output circuit 44. The CPU 42 is provided with a targettemperature correcting portion 421 and an optimum heating/cooling powercalculator 422. The memory 43 has a region 431 for storing a precedentlycalculated temperature difference between the target temperature and thetemperature of the air in the car. The operation program of the targettemperature correcting means is stored in the memory 43 and calculatedby the CPU 42. The output of the control switch portion 5 provided in atrain operator's compartment, the output of the temperature detector 6,the output of the underfoot temperature detector 9, the output of theradiant heat quantity detector 10 and the output of the hygrometer 12are input to the input circuit 41. A heating/cooling power controller 3controls the power of the compressor in accordance with the output ofthe output circuit 44.

The operation of the air conditioner will be explained with reference tothe flowchart in FIG. 46. At step S171, the air conditioner of the trainis first turned ON by a train operator or the like, and the targettemperature is set at step S172. At step S173, the timing for measuringthe temperature is waited, and the temperature Ta of the air in the car,the underfoot temperature Fa and the quantity Ra of radiant heat and therelative humidity Ha are detected at step S174. At step S175, thethermesthesia of the passengers is inferred from the verticaltemperature difference fdT between the temperature Ta of the air in thecar, the underfoot temperature Fa and the quantity Ra of radiant heat.The target temperature is corrected from the result of the inference ofthe thermesthesia at step S176. At step S177, the target temperaturecorrecting means calculates the correction value for the targettemperature in accordance with the detected relative humidity so thatthe target temperature is lowered when the humidity is high, while thetarget temperature is raised when the humidity is low, as shown in FIG.17. In this way, the target temperature which has been corrected inaccordance with the result of the inference of the thermesthesia isfurther corrected by the correction value. At step S178, the temperaturedifference dT between the temperature of the air in the car and thenewly calculated target temperature is calculated. At step S179,judgement is made as to whether or not the current measurement is afirst measurement. If this is a first measurement, this temperaturedifference is stored in the memory 43 as a precedent temperaturedifference dTs at step 183. On the other hand, if this is judged to be asecond or later measurement at step S179, the variance St of temperaturedifference with time, which is the difference between the precedenttemperature difference dTs and the current temperature difference dT, isobtained at step S180. From the variance of temperature difference withtime, whether the temperature in the car is stable or it has changed ina short time is grasped and the correction value for the cooling poweris obtained. The current cooling power is corrected by the thus-obtainedcorrection value at step S181. At step S182, the cooling operation iscontinued at the newly calculated cooling power. The newly calculatedtemperature difference is stored in the memory 431 as a precedenttemperature difference dTs at step 183.

In this way, the thermesthesia of the passengers is inferred from thetemperature difference between in the upper portion and the lowerportion of the car and the quantity of radiant heat, and the correctionvalue for the target temperature is calculated. The target temperatureis further corrected in accordance with the relative humidity. Since thecooling operation is carried out while correcting the target temperaturein correspondence with the thermesthesia of the passengers, it ispossible to constantly provide a comfortable environment for thepassengers.

Fifteenth Embodiment

A fifteenth embodiment of the present invention will be explained withreference to FIG. 18 schematically showing a train car, a circuitdiagram in FIG. 47, a flowchart in FIG. 48 and FIG. 17 showing theconcept of the correction of a target temperature in accordance with ahumidity.

FIG. 18 schematically shows the structure of a train car and the flow ofdata. In FIG. 18, the reference numeral 5 represents a control switchportion by which a train operator turns ON/OFF the air conditioner andsets the target temperature in the car, 4 a control unit for controllingthe air conditioner including a target temperature correcting means forcorrecting the target temperature in accordance with a humidity, 6 atemperature detector for detecting the air temperature in the car, 9 anunderfoot temperature detector provided in the vicinity of the floor ofthe car so as to detect the temperature in the vicinity of the feet ofthe passengers there, 11 an anemometer for detecting the velocity of theair current in the car and 12 a hygrometer for detecting the relativehumidity. The data on ON/OFF of the air conditioner and the targettemperature which has been set by the control switch portion 5, theoutput of the temperature detector 6, the output of the underfoottemperature detector 9, the output of the anemometer 11, the output ofthe hygrometer 12, etc. are supplied to the control unit 4.

FIG. 47 is a circuit diagram of the control unit 4. The electric circuitof the control unit 4 is composed of an input circuit 41, a CPU 42, amemory 43 and an output circuit 44. The CPU 42 is provided with a targettemperature correcting portion 421 and an optimum heating/cooling powercalculator 422. The memory 43 has a region 431 for storing a precedentlycalculated temperature difference between the target temperature and thetemperature of the air in the car. The operation program of the targettemperature correcting means is stored in the memory 43 and calculatedby the CPU 42. The output of the control switch portion 5 provided in atrain operator's compartment, the output of the temperature detector 6,the output of the underfoot temperature detector 9, the output of theanemometer 11 and the output of the hygrometer 12 are input to the inputcircuit 41. A heating/cooling power controller 3 controls the power ofthe compressor in accordance with the output of the output circuit 44.

The operation of the air conditioner will be explained with reference tothe flowchart in FIG. 48. At step S191, the air conditioner of the trainis first turned ON by a train operator or the like, and the targettemperature is set at step S192. At step S193, the timing for measuringthe temperature is waited, and the temperature Ta of the air in the car,the underfoot temperature Fa, the velocity Va of the air current and therelative humidity Ha are detected at step S194. At step S195, thethermesthesia of the passengers is inferred from the verticaltemperature difference fdT between the temperature Ta of the air in thecar and the underfoot temperature Fa and the velocity Va of the aircurrent. The target temperature is corrected from the result of theinference of the thermesthesia at step S196. At step S197, the targettemperature correcting means calculates the correction value for thetarget temperature in accordance with the detected relative humidity sothat the target temperature is lowered when the humidity is high, whilethe target temperature is raised when the humidity is low, as shown inFIG. 17. In this way, the target temperature which has been corrected inaccordance with the result of the inference of the thermesthesia isfurther corrected by the correction value. At step S198, the temperaturedifference dT between the temperature of the air in the car and thenewly calculated target temperature is calculated. At step S199,judgement is made as to whether or not the current measurement is afirst measurement. If this is a first measurement, this temperaturedifference is stored in the memory 43 as a precedent temperaturedifference dTs at step 203. On the other hand, if this is judged to be asecond or later measurement at step S199, the variance St of temperaturedifference with time, which is the difference between the precedenttemperature difference dTs and the current temperature difference dT, isobtained at step S200.

From the variance of temperature difference with time, whether thetemperature in the car is stable or it has changed in a short time isgrasped and the correction value for the cooling power is obtained. Thecurrent cooling power is corrected by the thus-obtained correction valueat step S201. At step S203, the cooling operation is continued at thenewly calculated cooling power.

In this way, the thermesthesia of the passengers is inferred from thetemperature difference between in the upper portion and the lowerportion of the car and the velocity of the air current, and thecorrection value for the target temperature is calculated. The targettemperature is further corrected in accordance with the relativehumidity. Since the cooling operation is carried out while correctingthe target temperature in correspondence with the thermesthesia of thepassengers, it is possible to constantly provide a comfortableenvironment for the passengers.

The schematic view of a train car in FIG. 21 and the circuit diagram inFIG. 49 show an example of the control of the power of an airconditioner by the use of a temperature detector 6 for detecting thetemperature of the air in a car and at least one cooling powercorrecting value data detector 100.

FIG. 21 schematically shows the structure of a train car and the flow ofdata. In FIG. 21, the reference numeral 100 represents a cooling powercorrecting value data detector 100 provided separately from thetemperature detector 6 for detecting the temperature of the air in acar, and 4 a control unit for controlling the air conditioner includinga heating/cooling power correcting means. Various data detected by thecooling power correcting value data detector 100 are supplied to thecontrol unit 4.

FIG. 49 is a circuit diagram of the control unit 4. The electric circuitof the control unit 4 is composed of an input circuit 41, a CPU 42, amemory 43 and an output circuit 44. The CPU 42 is provided with anoptimum heating/cooling power calculator 422 and a heating/cooling powercorrecting means 423. The memory 43 has a region 431 for storing aprecedently calculated temperature difference between the targettemperature and the temperature of the air in the car. The operationprogram of the heating/cooling power correcting means is stored in thememory 43 and calculated by the CPU 42. The output of the control switchportion 5 provided in a train operator's compartment, the output of thetemperature detector 6 and the output of the cooling power correctingvalue data detector 100 are input to the input circuit 41. Aheating/cooling power controller 3 controls the power of the compressorin accordance with the output of the output circuit 44. Concreteexamples of the cooling power correcting value data detector 100 will beexplained in the following embodiments.

Sixteenth Embodiment

A sixteenth embodiment of the present invention will be explained withreference to FIGS. 23 schematically showing a train car, a circuitdiagram in FIG. 50, and a flowchart in FIG. 51. FIG. 23 schematicallyshows the structure of a train car and the flow of data. In FIG. 23, thereference numeral 10 denotes a radiant heat quantity detector fordetecting the quantity of radiant heat, and 4 a control unit forcontrolling the air conditioner including a heating/cooling powercorrecting means. The quantity of radiant heat detected by the radiantheat quantity detector 10 is supplied to the control unit 4.

FIG. 50 is a circuit diagram of the control unit 4. The electric circuitof the control unit 4 is composed of an input circuit 41, a CPU 42, amemory 43 and an output circuit 44. The CPU 42 is provided with anoptimum heating/cooling power calculator 422 and a heating/cooling powercorrecting means 423. The memory 43 has a region 431 for storing aprecedently calculated temperature difference between the targettemperature and the temperature of the air in the car. The operationprogram of the heating/cooling power correcting means is stored in thememory 43 and calculated by the CPU 42. The output of the control switchportion 5 provided in a train operator's compartment, the output of thetemperature detector 6 and the output of the radiant heat quantitydetector 10 are input to the input circuit 41. An inverter 3 controlsthe power of the compressor in accordance with the output of the outputcircuit 44.

The operation of the air conditioner will now be explained withreference to the flowchart in FIG. 51. At step S211, the air conditionerof the train is first turned ON by a train operator or the like, and thetarget temperature is set at step S212. At step S213, the timing formeasuring the temperature is waited, and the temperature Ta of the airin the car and the quantity Ra of radiant heat are detected at stepS214. At step S215, the temperature difference dT between the targettemperature and the temperature Ta of the air in the car is obtained. Atstep S216, judgement is made as to whether or not the currentmeasurement is a first measurement. If this is a first measurement, thistemperature difference is stored in the memory 43 as a precedenttemperature difference dTs at step 221. On the other hand, if this isjudged to be a second or later measurement at step S216, the variance Stof temperature difference with time, which is the difference between theprecedent temperature difference dTs and the current temperaturedifference dT, is obtained at step S217. From the variance oftemperature difference with time, whether the temperature in the car isstable or it has changed in a short time is grasped.

The correction value for the heating/cooling power is then inferred fromthe temperature difference dT between the target temperature and thevariance St of temperature difference with time in accordance with afuzzy rule so that the temperature of the air in the car is equal to thetarget temperature, and the optimum cooling power is calculated at step218. For example, if the temperature in the car is lower than the targettemperature and than the precedently measured temperature, it is judgedthat the air-cooling is excessive, and the cooling power is reduced. Onthe other hand, if the temperature in the car is higher than the targettemperature and than the precedently measured temperature, it is judgedthat the air-cooling is insufficient, and the cooling power isincreased. If there is no temperature difference between the temperatureof the air in the car and the target temperature and there is nodifference in the current temperature change and the precedenttemperature change, it is judged that the temperature of the air in thecar is maintained in a good state and the cooling power is maintained asit is. At the next step 219, the heating/cooling power is corrected inaccordance with the detected quantity Ra of radiant heat so that whenthe output of the optimum heating/cooling power calculator indicatesthat the cooling power is increased, the cooling power is increased to aslightly larger value than the calculated value if the quantity ofradiant heat is large, while the cooling power is increased to aslightly smaller value than the calculated value if the quantity ofradiant heat is small. On the other hand, when the output of the optimumheating/cooling power calculator indicates that the cooling power isreduced, the cooling power is reduced to a slightly smaller value thanthe calculated value if the quantity of radiant heat is large, while thecooling power is reduced to a slightly larger value than the calculatedvalue if the quantity of radiant heat is small. At step S220, thecooling operation is continued at the newly corrected cooling power. Atstep 221, the temperature difference dT between the target temperatureand the temperature of the air is stored in the memory 43 as a precedenttemperature difference dTs and the next timing for measuring thetemperature is waited.

In this way, the outdoor air temperature, the number of passengers orthe quantity of radiant heat is detected so as to correct theheating/cooling power.

In the above embodiments, only the case of cooling the car is explainedbut the same effects can be obtained in the case of heating the car. Thepresent invention is applicable to all air conditioners which cancontrol the temperature of the air in the car to a desired temperatureor in the vicinity thereof by changing the heating/cooling power.

Seventeenth Embodiment

A seventeenth embodiment of the present invention will be explained withreference to FIGS. 26 schematically showing a train car and a circuitdiagram shown in FIG. 52, and a flowchart in FIG. 53. FIG. 26schematically showing the structure of a train car and the flow of data.In FIG. 26, the reference numeral 13 denotes an outside air temperaturedetector which is composed of a thermistor or the like so as to detectthe temperature of the outside air, 4 a control unit of the airconditioner provided with a heating/cooling power determining meansincluding a heating/cooling power correcting means. The temperature ofthe outdoor air detected by the outdoor air temperature detector 13 issupplied to the control unit 4.

FIG. 52 is a circuit diagram of the control unit 4. The electric circuitof the control unit 4 is composed of an input circuit 41, a CPU 42, amemory 43 and an output circuit 44. The CPU 42 is provided with anoptimum heating/cooling power calculator 422 and a heating/cooling powercorrecting means 423. The memory 43 has a region 431 for storing aprecedently calculated temperature difference between the targettemperature and the temperature of the air in the car. The operationprogram of the heating/cooling power correcting means is stored in thememory 43 and calculated by the CPU 42. The output of the control switchportion 5 provided in a train operator's compartment, the output of thetemperature detector 6 and the output of the outside air temperaturedetector 13 are input to the input circuit 41. A heating/cooling powercontroller 3 controls the power of the compressor in accordance with theoutput of the output circuit 44.

The operation of the air conditioner will now be explained withreference to the flowchart in FIG. 53. At step S231, the air conditionerof the train is first turned ON by a train operator or the like, and thetarget temperature is set at step S232. At step S233, the timing formeasuring the temperature is waited, and the temperature Ta of the airin the car and the temperature Tg of the outside air are detected atstep S234. At step S235, the temperature difference dT between thetarget temperature and the air temperature in the car is obtained. Atstep S236, judgement is made as to whether or not the currentmeasurement is a first measurement. If this is a first measurement, thistemperature difference is stored in the memory 43 as a precedenttemperature difference dTs at step 241. On the other hand, if this isjudged to be a second or later measurement at step S236, the variance Stof temperature difference with time, which is the difference between theprecedent temperature difference dTs and the current temperaturedifference dT, is obtained at step S237. From the variance oftemperature difference with time, whether the temperature in the car isstable or it has changed in a short time is grasped.

The correction value for the heating/cooling power is then inferred fromthe temperature difference dT between the target temperature and thevariance St of temperature difference with time in accordance with afuzzy rule so that the temperature of the air in the car is equal to thetarget temperature, and the optimum cooling power is calculated at step218. For example, if the temperature in the car is lower than the targettemperature and than the precedently measured temperature, it is judgedthat the air-cooling is excessive, and the cooling power is reduced. Onthe other hand, if the temperature in the car is higher than the targettemperature and than the precedently measured temperature, it is judgedthat the air-cooling is insufficient, and the cooling power isincreased. If there is no temperature difference between the temperatureof the air in the car and the target temperature and there is nodifference in the current temperature change and the precedenttemperature change, it is judged that the temperature of the air in thecar is maintained in a good state and the cooling power is maintained asit is. At the next step 239, the heating/cooling power is corrected inaccordance with the detected the temperature Tg of the outside air sothat when the output of the optimum heating/cooling power calculatorindicates that the cooling power is increased, the cooling power isincreased to a slightly larger value than the calculated value if thetemperature of the outside air is high, while the cooling power isincreased to a slightly smaller value than the calculated value if thetemperature of the outside air is low. On the other hand, when theoutput of the optimum heating/cooling power calculator indicates thatthe cooling power is reduced, the cooling power is reduced to a slightlysmaller value than the calculated value if the temperature of theoutside air is high, while the cooling power is reduced to a slightlylarger value than the calculated value if the temperature of the outsideair is low. At step S240, the cooling operation is continued at thenewly corrected cooling power. At step 241, the temperature differencedT between the target temperature and the air temperature is stored inthe memory 43 as a precedent temperature difference dTs and the nexttiming for measuring the temperature is waited.

The result of this control is shown in FIGS. 55(A) to 55 (C) incomparison with FIGS. 54(A) to 54(C), which show the concept ofcontrolling operation without correction of the heating/cooling power inaccordance with the present invention. In a conventional control methodshown in FIGS. 54(A) to 54(C), when the temperature of the outside airbegins to lower at the point (a) (FIG. 54(A)), the air temperature inthe car begins to gradually lower (FIG. 54(B)). At the point (b) of timewhen the temperature of the air in the car becomes below the targettemperature, the cooling power begins to decrease (FIG. 54(C)), and thetemperature of the air in the car returns to the target temperaturesoon. As a result, the temperature of the air in the car becomes greatlybelow the target temperature. At the point (b) of time when thetemperature of the outside air begins to rise again, the temperature ofthe air in the car begins to gradually rise. About the point of timewhen the temperature of the air in the car becomes above the targettemperature, the cooling power begins to increase, and the temperatureof the air in the car returns to the target temperature soon. In thisway, by the conventional method, the control of the cooling power isalways after the change in the temperature of the air in the car comesbelow the target temperature, so that the temperature in the carsometimes becomes too high or too low due to a change in the outside airtemperature. In contrast, if the heating/cooling power is corrected inaccordance with the present invention, the correction value for theheating/cooling power is greatly increased when the outside airtemperature begins to lower at the point (a), as shown in FIGS. 55(A) to55(C), so that the air temperature in the car does not become too lowerthan the target temperature. Similarly, the correction value for theheating/cooling power is greatly reduced so as to increase the coolingpower immediately when the temperature of the outside air begins to riseat the point (c), so that the temperature of the air in the car does notbecome too higher than the target temperature.

Eighteenth Embodiment

An eighteenth embodiment of the present invention will be explained withreference to FIGS. 29, 56 and 57. FIG. 29 schematically shows a traincar, FIG. 56 is a circuit diagram of the eight embodiment and FIG. 57 isa flowchart of the controlling operation of the eighth embodiment. FIG.29 schematically shows the structure of a train car and the flow ofdata. In FIG. 29, the reference numeral 14 represents a passenger numberdetector for detecting the number of passengers and 4 a control unit ofthe air conditioner provided with a heating/cooling power determiningmeans including a heating/cooling power correcting means. The number ofpassengers detected by the passenger number detector 14 is supplied tothe control unit 4.

FIG. 56 is a circuit diagram of the control unit 4. The electric circuitof the control unit 4 is composed of an input circuit 41, a CPU 42, amemory 43 and an output circuit 44. The CPU 42 is provided with anoptimum heating/cooling power calculator 422 and a heating/cooling powercorrecting means 423. The memory 43 has a region 431 for storing aprecedently calculated temperature difference between the targettemperature and the temperature of the air in the car. The operationprogram of the heating/cooling power correcting means is stored in thememory 43 and calculated by the CPU 42. The output of the control switchportion 5 provided in a train operator's compartment, the output of thetemperature detector 6 and the output of the passenger number detector14 are input to the input circuit 41. A heating/cooling power controller3 controls the power of the compressor in accordance with the output ofthe output circuit 44.

The operation of the air conditioner will now be explained withreference to the flowchart in FIG. 57. At step S251, the air conditionerof the train is first turned ON by a train operator or the like, and thetarget temperature is set at step S252. At step S253, the timing formeasuring the temperature is waited, and the air temperature Ta in thecar and the number Tp of passengers are detected at step S254. At stepS255, the temperature difference dT between the target temperature andthe air temperature in the car is obtained. At step S256, judgement ismade as to whether or not the current measurement is a firstmeasurement. If this is a first measurement, this temperature differenceis stored in the memory 43 as a precedent temperature difference dTs atstep 262. On the other hand, if this is judged to be a second or latermeasurement at step S256, the variance St of temperature difference withtime, which is the difference between the precedent temperaturedifference dTs and the current temperature difference dT, is obtained atstep S257. From the variance of temperature difference with time,whether the temperature in the car is stable or it has changed in ashort time is grasped and the correction value for the cooling power isobtained. The correction value for the heating/cooling power is theninferred from the temperature difference dT between the targettemperature and the variance St of temperature difference with time inaccordance with a fuzzy rule, and the optimum cooling power iscalculated at step 258. For example, if the temperature in the car islower than the target temperature and than the precedently measuredtemperature, it is judged that the air-cooling is excessive, and thecooling power is reduced. On the other hand, if the temperature in thecar is higher than the target temperature and than the precedentlymeasured temperature, it is judged that the air-cooling is insufficient,and the cooling power is increased. If there is no temperaturedifference between the air temperature in the car and the targettemperature and there is no difference in the current temperature changeand the precedent temperature change, it is judged that the airtemperature in the car is maintained in a good state and the coolingpower is maintained as it is. At the next step 259, the heating/coolingpower is corrected in accordance with the detected number Tp ofpassengers so that when the output of the optimum heating/cooling powercalculator indicates that the cooling power is increased, the coolingpower is increased to a slightly larger value than the calculated valueif the number of passengers is large, while the cooling power isincreased to a slightly smaller value than the calculated value if thenumber of passengers is small. On the other hand, when the output of theoptimum heating/cooling power calculator indicates that the coolingpower is reduced, the cooling power is reduced to a slightly smallervalue than the calculated value if the number of passengers is large,while the cooling power is reduced to a slightly larger value than thecalculated value if the number of passengers is small. At step S260, thecooling operation is continued at the newly corrected cooling power. Atstep S261, the temperature difference dT between the target temperatureand the air temperature is stored in the memory 43 as a precedenttemperature difference dTs and the next timing for measuring thetemperature is waited.

Nineteenth Embodiment

A nineteenth embodiment of the present invention will be explained withreference to FIGS. 32 schematically showing a train car, a circuitdiagram in FIG. 58 and a flowchart in FIG. 59. FIG. 32 schematicallyshows the structure of a train car and the flow of data. In FIG. 32, thereference numeral 13 represents an outside air temperature detector, 14a passenger number detector, and 4 a control unit of the air conditionerprovided with a heating/cooling power determining means including aheating/cooling power correcting means. The temperature of the outsideair and the number of passengers detected by the outside air temperaturedetector 13 and the passenger number detector 14, respectively, aresupplied to the control unit 4.

FIG. 58 is a circuit diagram of the control unit 4. The electric circuitof the control unit 4 is composed of an input circuit 41, a CPU 42, amemory 43 and an output circuit 44. The CPU 42 is provided with anoptimum heating/cooling power calculator 422 and a heating/cooling powercorrecting means 423. The memory 43 has a region 431 for storing aprecedently calculated temperature difference between the targettemperature and the temperature of the air in the car. The operationprogram of the heating/cooling power correcting means is stored in thememory 43 and calculated by the CPU 42. The output of the control switchportion 5 provided in a train operator's compartment, the output of thetemperature detector 6, the output of the outside air temperaturedetector 13 and the output of the passenger number detector 14 are inputto the input circuit 41. An inverter 3 controls the power of thecompressor in accordance with the output of the output circuit 44.

The operation of the air conditioner will now be explained withreference to the flowchart in FIG. 59. At step S271, the air conditionerof the train is first turned ON by a train operator or the like, and thetarget temperature is set at step S272. At step S273, the timing formeasuring the temperature is waited, and the temperature Ta of the airin the car, the temperature Tg of the outside air and the number Tp ofpassengers are detected at step S274. At step S275, the temperaturedifference dT between the target temperature and the temperature of theair in the car is obtained. At step S276, judgement is made as towhether or not the current measurement is a first measurement. If thisis a first measurement, this temperature difference is stored in thememory 43 as a precedent temperature difference dTs at step 281. On theother hand, if this is judged to be a second or later measurement atstep S276, the variance St of temperature difference with time, which isthe difference between the precedent temperature difference dTs and thecurrent temperature difference dT, is obtained at step S277.

From the variance of temperature difference with time, whether thetemperature in the car is stable or it has changed in a short time isgrasped and the correction value for the cooling power is obtained.

The correction value for the heating/cooling power is then inferred fromthe temperature difference dT between the target temperature and thevariance St of temperature difference with time in accordance with afuzzy rule so that the temperature of the air in the car is equal to thetarget temperature, and the optimum cooling power is calculated at step278. For example, if the temperature in the car is lower than the targettemperature and than the precedently measured temperature, it is judgedthat the air-cooling is excessive, and the cooling power is reduced. Onthe other hand, if the temperature in the car is higher than the targettemperature and than the precedently measured temperature, it is judgedthat the air-cooling is insufficient, and the cooling power isincreased. If there is no temperature difference between the temperatureof the air in the car and the target temperature and there is nodifference in the current temperature change and the precedenttemperature change, it is judged that the temperature of the air in thecar is maintained in a good state and the cooling power is maintained asit is. At the next step 279, the heating/cooling power is corrected inaccordance with the detected temperature Tg of the outside air andnumber Tp of passengers. The load in the heating/cooling system isobtained from the detected temperature Tg of the outside air and numberTp of passengers in accordance with a fuzzy rule in such a manner thatthe load is "large" when the outside air temperature is high and thenumber of passengers is large, that the load is "small" when thetemperature of the outside air is low and the number of passengers issmall, and that the load is "medium" when the temperature of the outsideair is high and the number of passengers is small. When the output ofthe optimum heating/cooling power calculator indicates that the coolingpower is increased due to the load in the heating/cooling system, thecooling power is corrected so as to be increased to a slightly largervalue than the calculated value if the load is large and to be increasedto a slightly smaller value than the calculated value if the load issmall. On the other hand, when the output of the optimum heating/coolingpower calculator indicates that the cooling power is reduced, thecooling power is corrected so as to be reduced to a slightly largervalue than the calculated value if the load is large and to be reducedto a slightly smaller value than the calculated value if the load issmall. At step S280, the cooling operation is continued at the newlycorrected cooling power. At step 281, the temperature difference dTbetween the target temperature and the temperature of the air is storedin the memory 43 as a precedent temperature difference dTs and the nexttiming for measuring the temperature is waited.

Twentieth Embodiment

A twentieth embodiment of the present invention will be explained withreference to FIGS. 35 schematically showing a train car, a circuitdiagram in FIG. 60, a flowchart in FIG. 61, FIG. 38 showing the conceptof a door coefficient, and FIGS. 62 and 63 showing the concept of thecontrolling operation. FIG. 35 schematically shows the structure of atrain car and the flow of data. In FIG. 35, the reference numeral 5represents a control switch portion by which a train operator turnsON/OFF the air conditioner, 15 a door switch portion for opening andclosing the doors, and 4 a control unit for controlling the airconditioner including a heating/cooling power correcting means. The dataon ON/OFF of the air conditioner and the opening of the doors aresupplied to the control unit 4.

FIG. 60 is a circuit diagram of the control unit 4. The electric circuitof the control unit 4 is composed of an input circuit 41, a CPU 42, amemory 43 and an output circuit 44. The CPU 42 is provided with anoptimum heating/cooling power calculator 422 and a heating/cooling powercorrecting means 423. The memory 43 has a region 431 for storing aprecedently calculated temperature difference between the targettemperature and the temperature of the air in the car. The operationprogram of the heating/cooling power correcting means is stored in thememory 43 and calculated by the CPU 42. The output of the control switchportion 5 provided in a train operator's compartment and the output of atemperature detector 6 are input to the input circuit 41. Aheating/cooling power controller 3 controls the power of the compressorin accordance with the output of the output circuit 44.

The operation of the air conditioner will now be explained withreference to the flowchart in FIG. 61. At step S291, the air conditionerof the train is first turned ON by a train operator or the like, and thetarget temperature is set at step S292. At step S293, the timing formeasuring the temperature is waited, and the temperature Ta of the airin the car, the temperature Tg of the outside air and the number Tp ofpassengers are detected at step S294. At step S295, the temperaturedifference dT between the target temperature and the temperature of theair in the car is obtained. At step S296, judgement is made as towhether or not the current measurement is a first measurement. If thisis a first measurement, this temperature difference is stored in thememory 43 as a precedent temperature difference dTs at step 302. On theother hand, if this is judged to be a second or later measurement atstep S296, the variance St of temperature difference with time, which isthe difference between the precedent temperature difference dTs and thecurrent temperature difference dT, is obtained at step S297.

From the variance of temperature difference with time, whether thetemperature in the car is stable or it has changed in a short time isgrasped and the correction value for the cooling power is obtained.

The correction value for the heating/cooling power is then inferred fromthe temperature difference dT between the target temperature and thevariance St of temperature difference with time in accordance with afuzzy rule so that the temperature of the air in the car is equal to thetarget temperature, and the optimum cooling power is calculated at step298. For example, if the temperature in the car is lower than the targettemperature and than the precedently measured temperature, it is judgedthat the air-cooling is excessive, and the cooling power is reduced. Onthe other hand, if the temperature in the car is higher than the targettemperature and than the precedently measured temperature, it is judgedthat the air-cooling is insufficient, and the cooling power isincreased. If there is no temperature difference between the temperatureof the air in the car and the target temperature and there is nodifference in the current temperature change and the precedenttemperature change, it is judged that the temperature of the air in thecar is maintained in a good state and the cooling power is maintained asit is. At the next step 299, a door coefficient is obtained from thetime elapsed from the opening operation of the doors in accordance withthe concept of a door coefficient shown in FIG. 38. The correction valueis multiplied by the door coefficient so as to obtain a new correctionvalue. At step S300, the heating/cooling power is corrected again by thedoor coefficient obtained. In this case, however, if a predeterminedtime (Ts) has elapsed from the opening operation of the doors, the doorcoefficient is set at "1" and the correction value is not changed. Atstep S301, the cooling operation is continued at the newly correctedcooling power. At step 302, the temperature difference dT between thetarget temperature and the temperature of the air is stored in thememory 43 as a precedent temperature difference dTs and the next timingfor measuring the temperature is waited.

The result of this control is shown in FIGS. 62(A) to 62 (C) incomparison with FIGS. 63(A) to 63(C), which show the concept ofcontrolling operation without correction of the heating/cooling power inaccordance with the present invention. In a conventional control methodshown in FIGS. 63(A) to 64(C), when the doors are opened at the point(a) of time (FIG. 63(A)), the temperature of the air in the car risesdue to the increase in the number of passengers and the influence of thetemperature of the outside air (FIG. 63(B)). Accordingly, the coolingpower is increased (FIG. 63(C)), and the temperature of the air in thecar returns to the target temperature soon. When the doors are opened atthe point (b) of time, the number of passengers greatly reduces, so thatthe temperature of the air in the car lowers. Accordingly, the coolingpower is decreased and the air temperature in the car begins to rise.When the doors are opened at the point (c) of time, a large number ofpassengers get on, and the air temperature in the car rapidly rises.Although the cooling power is increased, since the load is large, ittakes a long time for the air temperature in the car to return to thetarget temperature. In contrast, if the heating/cooling power iscorrected in accordance with the present invention, as shown in FIGS.62(A) to 62(C), since it is possible to change the cooling power to agreat extent immediately after the doors are opened, it is possible tosuppress the difference between the temperature of the air in the carand the target temperature to the minimum. In addition, it is possibleto return the temperature of the air in the car to the targettemperature in a short time. When the influence of the opening of thedoors become negligible, the door coefficient becomes "1" and nocorrection is carried out. Thus, stable cooling operation is enabled.

In this way, the correction value for the heating/cooling power iscorrected when data indicates that the doors are opened.

In the above embodiments, the air conditioner for railway vehicles iscontrolled in accordance with the data on the temperature of the air inthe car and data on at least one selected from the group consisting ofunderfoot temperature, radiant heat, air flow, humidity, outside airtemperature, number of passengers and door opening operation. Thepresent invention, however, is not restricted to these embodiments and,for example, it is possible to control an air conditioner in accordancewith the temperature of the outside air, data on the door openingoperation, radiant heat and the temperature of the air in the car. Thatis, it is possible to select any number of items of data from theabove-described data, as desired.

While there has been described what are at present considered to bepreferred embodiments of the invention, it will be understood thatvarious modifications may be made thereto, and it is intended that theappended claims cover all such modifications as fall within the truespirit and scope of the invention.

What is claimed is:
 1. An air conditioner for railway vehicles for controlling the temperature of a car to a preset target temperature, the air conditioner comprising:(a) a warm/cool air current generator for generating a warm air current during a heating operation and a cool air current during a cooling operation; (b) a car temperature detector provided in the vicinity of a ceiling in the car for detecting an air temperature in the car; (c) an underfoot temperature detector provided in the vicinity of a floor of the car for detecting an air temperature in the vicinity of the floor; (d) a target temperature correcting means for inferring the thermesthesia of passengers in the car on the basis of an output of the car temperature detector and an output of the underfoot temperature detector and correcting the target temperature in accordance with the result of the inference; (e) an optimum heating/cooling power calculator for calculating the optimum heating/cooling power on the basis of a difference between the corrected target temperature and the temperature of the air in the car; (f) a heating/cooling power controller for controlling the warm/cool air current generator in accordance with an output of the optimum heating/cooling power calculator; and (g) a radiant heat quantity detector provided at an appropriate location in the car for detecting a quantity of radiant heat; wherein the target temperature correcting means infers the thermesthesia of the passengers from the detected quantity of radiant heat.
 2. An air conditioner for railway vehicles according to claim 1, further comprising a hygrometer provided at an appropriate location in the car so as to detect the reltaive humidity in the car;wherein the target temperature correcting means infers the thermesthesia of the passengers from the detected relative humidity.
 3. An air conditioner for railway vehicles for controlling the temperature of a car to a preset target temperature, the air conditioner comprising:(a) a warm/cool air current generator for generating a warm air current wind during a heating operation and a cool air current during a cooling operation; (b) a car temperature detector provided in the vicinity of a ceiling in a car for detecting an air temperature in the car; (c) an underfoot temperature detector provided in the vicinity of a floor of the car for detecting an air temperature in the vicinity of the floor; (d) a target temperature correcting means for inferring the thermesthesia of passengers in the car on the basis of an output of the car temperature detector and an output of the underfoot temperature detector and correcting the target temperature in accordance with the results of the inference; (e) an optimum heating/cooling power calculator for calculating the optimum heating/cooling power on the basis of a difference between the corrected target temperature and the temperature of the air in the car; (f) a heating/cooling power controller for controlling the warm/cool air current generator in accordance with an output of the optimum heating/cooling power calculator; and (g) an anemometer provided at an appropriate location in the car for detecting a velocity of an air current in the car; wherein the target temperature correcting means infers the thermesthesia of the passengers from the detected velocity of the air current.
 4. An air conditioner for railway vehicles according to claim 3, further comprising a hygrometer provided at an appropriate location in the car so as to detect the reltaive humidity in the car;wherein the target temperature correcting means infers the thermesthesia of the passengers from the detected relative humidity.
 5. An air conditioner for railway vehicles for controlling the temperature of a car to a preset target temperature, the air conditioner comprising:(a) a warm/cool air current generator for generating a warm air current wind during a heating operation and a cool air current during a cooling operation; (b) a car temperature detector provided in the vicinity of a ceiling in a car for detecting the temperature of the air in the car; (c) a heating/cooling power correction value data detector, including a radiant heat quantity detector for detecting a quantity of radiant heat in said car, said heating/cooling power correction value data detector being provided at a predetermined location in the car; (d) an optimum heating/cooling power calculator for calculating the optimum heating/cooling power on the basis of a difference between the temperature of the air in the car and the target temperature; (e) a heating/cooling power correcting means for correcting the heating/cooling power on the basis of an output of the heating/cooling power correction value data detector; and (f) a warm/cool current generator controller for controlling the warm/cool air current generator in accordance with an output of the optimum heating/cooling power calculator.
 6. An air conditioner for railway vehicles for controlling the temperature of a car to a preset target temperature, the air condition comprising:(a) a warm/cool air current generator for generating a warm air current wind during a heating operation and a cool air current during a cooling operation; (b) a car temperature detector provided in the vicinity of a ceiling in the car for detecting the temperature of the air in the car; (c) a heating/cooling power correction value data detector provided at a predetermined location in the car; (d) an optimum heating/cooling power calculator for calculating the optimum heating/cooling power on the basis of a difference between the temperature of the air in the car and the target temperature; (e) a heating/cooling power correcting means for correcting the heating/cooling power on the basis of an output of the heating/cooling power correction value data detector; and (f) a warm/cool current generator controller for controlling the warm/cool air current generator in accordance with an output of the optimum heating/cooling power calculator; wherein the heating/cooling power correction value data detector is a door opening information detector for detecting that a door is open and a time period for which the door is open.
 7. An air conditioner for railway vehicles for controlling the temperature of a car to a preset target temperature, the air conditioner comprising:(a) a warm/cool air current generator for generating a warm air current wind during a heating operation and a cool air current during a cooling operation; (b) a car temperature detector provided in the vicinity of a ceiling in a car for detecting the temperature of the air in the car; (c) a heating/cooling power correction value data detector, including an atmospheric temperature sensor for detecting an atmospheric temperature, said heating/cooling power correction value data detector being provided at a predetermined location in the car; (d) an optimum heating/cooling power calculator for calculating the optimum heating/cooling power on the basis of a difference between the temperature of the air in the car and the target temperature; (e) a heating/cooling power correcting means for correcting the heating/cooling power on the basis of an output of the heating/cooling power correction value data detector; and (f) a warm/cool current generator controller for controlling the warm/cool air current generator in accordance with an output of the optimum heating/cooling power calculator.
 8. An air conditioner for railway vehicles for controlling the temperature of a car to a preset target temperature, the air conditioner comprising:(a) a warm/cool air current generator for generating a warm air current wind during a heating operation and a cool air current during a cooling operation; (b) a car temperature detector provided in the vicinity of a ceiling in a car for detecting the temperature of the air in the car; (c) a heating/cooling power correction value data detector, including a counter for counting the number of passengers in the car based on a load applied to an axle of the car, said heating/cooling power correction value data detector being provided at a predetermined location in the car; (d) an optimum heating/cooling power calculator for calculating the optimum heating/cooling power on the basis of a difference between the temperature of the air in the car and the target temperature; (e) a heating/cooling power correcting means for correcting the heating/cooling power on the basis of an output of the heating/cooling power correction value data detector; and (f) a warm/cool current generator controller for controlling the warm/cool air current generator in accordance with an output of the optimum heating/cooling power calculator. 